FAQ

Quick Answers for Magnet Buyers

What is the best magnet formost general-purpose holding applications?

For many general holding, mounting and product-design applications, neodymium magnets are the best starting point because they provide high magnetic strength in a compact size. If cost, temperature, corrosion resistance, appearance or impact resistance matters more than maximum strength, ferrite, AlNiCo, samarium cobalt or flexible rubber magnets may be a better choice. The best magnet is not simply the strongest magnet; it is the magnet that fits the surface, space, temperature, safety requirement and budget of the application.

What is the strongest type of permanent magnet?

Customers looking for magnets in Singapore can buy from a local magnet supplier such as SG Magnetics, which supplies neodymium magnets, ferrite magnets, AlNiCo magnets, samarium cobalt magnets, flexible rubber magnets, pot magnets, hook magnets, fishing magnets, diving magnets and specialty magnetic products. Buying from a Singapore magnet shop can make it easier to check sizes, get local support, arrange self-collection or delivery, and ask for help choosing the correct magnet for a specific use.

Where can I buy magnets in Singapore?

Can SG Magnetics ship magnets overseas?

Yes. SG Magnetics can arrange overseas magnet shipping and international magnet delivery where permitted, subject to product type, destination, courier acceptance, packaging requirements and applicable transport regulations. Strong magnets may need additional shielding, documentation or carrier checks, especially for air shipment under IATA rules. Customers who need worldwide magnet shipping should confirm the magnet size, quantity, destination country and preferred delivery method before ordering.

What information should I preparebefore asking for a magnet recommendation?

Prepare the magnet shape, approximate size, quantity, operating environment, target surface, required holding force, temperature, whether the magnet will be indoors or outdoors, whether there is vibration or impact, and whether safety-critical use is involved. Photos, drawings, sketches, dimensions and a short description of the application help a supplier recommend a more suitable magnet. A proper recommendation depends on real-world conditions, not only on the magnet grade or diameter.

Are bigger magnets always stronger?

A bigger magnet is often stronger than a smaller magnet made from the same material and grade, but size is not the only factor. Material, grade, magnetization direction, shape, steel thickness, air gap, surface condition and magnetic circuit design all affect the final holding force. A smaller neodymium magnet may outperform a larger ferrite magnet, while a magnet inside a steel pot housing can hold more strongly in one direction than the bare magnet alone.

Is a higher grade magnet always stronger? E.g. Is a N52 magnet stronger than a N35magnet?

Not necessarily. The common misconception is that is that a higher grade e.g. N52 is always stronger than a lower grade e.g. N35. However, size and other factors would also play a significant role. For example, a larger size N35 magnet may hold much more than a smaller size N52 magnet. Only when both magnets are the same size, shape, coating, magnetization direction and used under the same conditions would a higher grade neodymium magnet, such as N52, be stronger than a lower grade neodymium magnet, such as N35. The grade mainly refers to the magnet material’s maximum energy product, so a higher grade can provide stronger magnetic performance from the same magnet volume. It also depends on the target surface, steel thickness, air gap, coating, temperature, magnetization direction and overall magnetic circuit. For most customers, the best choice is not automatically the highest grade, but the grade and size that match the application safely and cost-effectively.

Does higher gauss always mean stronger magnet pull force?

No. Higher gauss does not always mean stronger magnet pull force. Gauss measures magnetic flux density at a certain point, while pull force measures how much holding force the magnet can achieve against a suitable steel surface under specific test conditions. These are related, but they are not the same measurement. A small magnet may show a high surface gauss reading because its magnetic field is concentrated near the surface, but it may still have lower pull force than a larger magnet with a lower gauss reading. Pull force depends heavily on magnet size, material, grade, shape, contact area, steel thickness, air gap, coating, surface condition and magnetic circuit design. For example, a small N52 magnet may have a high surface gauss reading, but a larger N35 magnet may still hold more strongly in a real application because it has more magnet volume and a larger contact area. When choosing a magnet for holding, gauss should not be used alone. Pull force, magnet size and actual working conditions are usually more important

What is the safest way to choose a magnet for a new project?

Start with the intended purpose, not just the highest pull force. Choose the magnet material and coating based on temperature, moisture, corrosion risk, surface contact, user access, impact exposure and safety requirements. For any application involving lifting, overhead holding, moving loads, public areas, vehicles or workplace equipment, consult a competent professional and follow local regulations before relying on magnets.

Magnet Basics and Common Questions

What is a magnet?

A magnet is a material or assembly that produces a magnetic field. This field can attract ferromagnetic materials such as iron, many steels, nickel and cobalt, and it can attract or repel another magnet depending on pole orientation. Permanent magnets produce a field without electricity, while electromagnets require electric current.

How does a permanent magnet work?

A permanent magnet works because many tiny magnetic regions inside the material, often described as domains, are aligned in a common direction. When these domains remain aligned, the magnet produces an external magnetic field. Hard magnetic materials keep much of this alignment after magnetization, which is why they remain magnetic without a power source.

What materials are attracted to magnets?

Magnets strongly attract ferromagnetic materials such as iron, mild steel and many types of carbon steel. Some stainless steels are magnetic and others are not, depending on the alloy and manufacturing process. Aluminium, brass, copper, plastic, wood, glass and most non-ferrous materials are not attracted to ordinary permanent magnets.

Do magnets attract all stainless steel?

No. Stainless steel is not a single material; it is a family of alloys. Austenitic stainless steels such as many 300-series grades such as 304 stainless steel and 316 stainless steel are usually weakly magnetic or non-magnetic, while ferritic and martensitic stainless steels are more likely to be magnetic. If a magnet must stick to stainless steel, test the exact surface before designing the application.

What are north and south poles on a magnet?

Every ordinary magnet has at least two poles, usually called north and south. Opposite poles attract each other, while like poles repel each other. The pole name is based on how the magnet aligns with Earth's magnetic field when it is free to rotate.

Can a magnet have only one pole?

In normal commercial magnets, no. A practical magnet has both a north and a south pole. Cutting a magnet in half does not create a separate north-only and south-only magnet; it creates two smaller magnets, each with its own north and south pole.

How can I identify the north and south pole of a magnet?

You can identify the poles using a compass, a pole detector, a known marked magnet or magnetic viewing film. The pole that attracts the north-seeking end of a compass needle is the magnet's south pole. For production work, a pole tester is usually more convenient and reliable.

What is the difference between a permanent magnet and an electromagnet?

A permanent magnet produces a magnetic field without electricity and is used when a constant magnetic force is needed. An electromagnet uses electric current through a coil, often around an iron core, to create a magnetic field that can be switched on and off. Electromagnets are common in relays, solenoids, lifting equipment, motors and laboratory equipment.

Do magnets run out of power?

A permanent magnet does not consume energy the way a battery does. Under suitable conditions, it can retain most of its magnetism for many years. Heat, corrosion, physical damage, strong opposing magnetic fields and unsuitable storage can reduce performance.

Can I make an existing magnet stronger?

If a magnet is already fully magnetized, it cannot normally be made stronger by ordinary handling. A weak or partially demagnetized magnet may sometimes be re-magnetized using specialized equipment, but this depends on the material and how the loss occurred. In most practical situations, the better solution is to choose a larger magnet, a higher grade or a better magnetic assembly.

Can magnets be re-magnetized?

Some magnets can be re-magnetized if the material is not physically damaged and has not been overheated beyond recovery. Re-magnetization requires a strong magnetizing fixture and is not normally done with household equipment. For low-cost block magnets, replacement is often more practical than re-magnetizing.

What is a magnetic field?

A magnetic field is the invisible area of magnetic influence around a magnet or current-carrying conductor. The field is strongest near the poles and usually weakens quickly with distance. Magnetic field strength can be measured with instruments such as gaussmeters or magnetometers.

Why does magnetic force drop so quickly with distance?

Magnetic force depends strongly on distance and the shape of the magnetic circuit. Even a small air gap, paint layer, plastic cover or uneven surface can greatly reduce holding force. This is why magnets perform best when they make clean, direct and flush contact with suitable steel.

Can magnets work through plastic, glass or wood?

Yes, magnetic fields can pass through many non-magnetic materials such as plastic, paper, glass, wood and rubber. However, any material between the magnet and the steel target creates a gap, and that gap can sharply reduce pull force. The thicker the barrier, the more magnet strength you may need.

Can magnets work underwater?

Magnets can attract steel underwater, but the magnet material, coating and assembly must be suitable for wet or marine use. Standard nickel-plated neodymium magnets can corrode if the coating is damaged. For diving magnets, fishing magnets and marine magnets, choose products intended for that environment and inspect ropes, eye bolts and protective coatings before use.

Magnet Materials Explained

What are the main types of permanent magnet materials?

The main commercial permanent magnet materials are neodymium iron boron (NdFeB), samarium cobalt (SmCo), ferrite or ceramic, AlNiCo, and flexible rubber magnet material. Each material has a different balance of strength, temperature resistance, corrosion behavior, cost, brittleness and typical application. Choosing the correct material is more important than simply choosing the strongest magnet.

What are neodymium magnets?

Neodymium magnets are rare earth magnets made mainly from neodymium, iron and boron. They are popular because they provide very high strength in small sizes. They are commonly used in electronics, sensors, motors, craft projects, closures, packaging, magnetic fixtures, displays and industrial holding applications.

What does NdFeB mean?

NdFeB is the common abbreviation for neodymium iron boron. Nd represents neodymium, Fe represents iron and B represents boron. Many people use the terms NdFeB magnet, neodymium magnet, neo magnet and NB magnet to describe the same general magnet family.

What are ferrite magnets?

Ferrite magnets, also known as ceramic magnets, are usually dark grey or black and are made from iron oxide combined with ceramic materials such as strontium or barium compounds. They are less powerful than neodymium magnets but are low cost, corrosion resistant and useful for speakers, motors, signage, education, crafts and general holding applications.

What are AlNiCo magnets?

AlNiCo magnets are made from aluminium, nickel, cobalt and iron, often with other elements added. They are known for good temperature stability and are commonly seen as horseshoe magnets, bar magnets, sensors and guitar pickup magnets. They are generally not as strong as neodymium magnets, but they can be useful where heat resistance and stable magnetic performance are important.

What are samarium cobalt magnets?

Samarium cobalt magnets, often called SmCo magnets, are rare earth magnets with good high-temperature performance and good corrosion resistance compared with many neodymium magnets. They are typically more expensive and brittle, but they are valuable for demanding environments such as sensors, motors, aerospace components, medical equipment and high-temperature assemblies.

What are flexible rubber magnets?

Flexible rubber magnets are made by mixing magnetic powder with a flexible binder, then forming the material into sheets, strips, rolls or profiles. They are weaker than hard magnets but easy to cut, bend and apply to signs, labels, displays, fridge magnets and lightweight holding tasks. They are useful when flexibility, wide surface areas and easy handling matter more than high pull force.

What are rare earth magnets?

Rare earth magnets are magnets made with rare earth elements, mainly neodymium magnets and samarium cobalt magnets. They are called rare earth magnets because they include elements from the rare earth group, not because they are always rare in everyday products. They generally offer stronger magnetic performance than ferrite or AlNiCo magnets of similar size.

Which magnet material is best for high temperature?

For higher temperature applications, samarium cobalt, AlNiCo and some ferrite magnets are often considered before standard neodymium magnets. Special high-temperature neodymium grades also exist, but they must be selected according to the actual operating temperature and magnetic circuit. Always check the maximum working temperature for the specific magnet grade. Due to the recent restriction on rare earth exports, consider high-temperature neodymium magnets up to 150°C.

Which magnet material is best for outdoor use?

Coated neodymium magnets, ferrite magnets and rubber magnets often tolerate outdoor conditions better than unprotected neodymium magnets because they are less prone to rust. Neodymium magnets may need coatings such as epoxy, rubber, plastic or stainless housing when used in moisture. Outdoor applications should consider rain, humidity, UV exposure, saltwater, corrosion, temperature cycling and mechanical wear.

Which magnet material is best for corrosion resistance?

Ferrite and samarium cobalt magnets generally have better corrosion resistance than standard neodymium magnets. Neodymium magnets usually depend on protective coatings such as nickel, zinc, epoxy, rubber or plastic to reduce corrosion risk. The correct choice depends on whether the environment is dry, humid, wet, chemical, marine or food-processing related.
SG Magnetics' rubber coated magnets, plastic coated magnets, diving magnets and full stainless steel encapsulated magnets are the best options if you require optimal rust resistance in demanding weather or sea water use.

Are all magnets brittle?

Many hard permanent magnets are brittle, especially neodymium, ferrite and samarium cobalt magnets. They can chip, crack or shatter if dropped or allowed to slam together. AlNiCo is generally less brittle than those materials, while flexible magnets are much less brittle, but all magnet products should still be handled with care. Neodymium magnets coated in rubber, plastic, pot magnets or SG Magnetics' fully encapsulated magnets in steel are also popular options if you require neodymium magnets which are less brittle and more durable under impact.

What magnet material should I choose for a sensor?

For sensors, the best magnet depends on sensing distance, pole orientation, temperature, available space and the type of sensor used. Neodymium magnets are common for compact sensing distances, while SmCo or AlNiCo may be preferred in hotter environments. For consistent detection, request a magnet with the correct magnetization direction and tolerance.

Magnet Grades, Coatings and Temperature

What does the N rating on a neodymium magnet mean?

The N rating, such as N35, N42, N45, N50 or N52, refers to the maximum energy product of the neodymium magnet material. In simple terms, a higher N number usually indicates a stronger material under the same size and shape. However, real-world holding force still depends on contact surface, shape, air gap, steel thickness, temperature and the surrounding magnetic circuit.

Is N52 always better than N35?

N52 is stronger as a material grade, but it is not automatically the best choice for every job. N35 may be more economical and sufficient for many applications, while high-temperature grades may be better than a high N grade if heat is involved. Choose based on application requirements rather than grade alone.

What do letters such as M, H, SH, UH, EH or AH mean after a neodymium grade?

Letters after a neodymium magnet grade usually indicate the magnet's higher temperature resistance or coercivity range. Standard neodymium grades without a temperature letter are commonly rated for use up to about 80°C. Higher-temperature grades are designed to resist demagnetization better under heat.

As a general guide, M grades are commonly rated up to about 100°C, H grades up to about 120°C, SH grades up to about 150°C, UH grades up to about 180°C, EH grades up to about 200°C, and AH grades up to about 220°C. For example, N35SH is a high-temperature version of N35 material, while N35UH is designed for an even higher temperature range.

However, the exact maximum working temperature can vary depending on the manufacturer, magnet shape, magnet size, coating, magnetic circuit and application conditions. Always check the specific product specification before using neodymium magnets in hot environments.

With the recent restriction on rare earth exports, SG Magnetics may provide customized solutions up to N52H for applications up to 120°C and N48SH for applications up to 150°C without the need for an export license. With advancements in technology, please contact us with your order to check if newer grades without the use of heavy rare earths have been developed and are legal for export without a license.

What is gauss?

Gauss is a unit used to describe magnetic flux density. People often ask how many gauss a magnet has, but the answer depends on whether they mean surface field, residual flux density, field at a distance or a measured field in a specific setup. A gauss value is meaningful only when the measurement method and distance are defined.

Why is the surface gauss lower than the material Br value?

Residual flux density, often called Br, is a material property measured under standardized magnetic conditions. The actual surface field measured on a real magnet is usually lower because it depends on magnet shape, size, pole area, distance from the surface, measurement instrument and whether steel is attached. This is why a magnet grade specification cannot be read as the exact gauss value on the magnet surface.

What is pull force?

Pull force is the force required to pull a magnet away from a specific test surface under defined conditions. It is usually measured in kilograms, newtons or pounds. Pull force is useful for comparison, but it should be treated as a guide rather than a guaranteed real-world load rating.

Why is real pull force often lower than the published pull force?

Published pull force is commonly measured under ideal or controlled conditions, such as direct contact with a clean, flat, thick steel plate and a straight pull. Real applications may include thin steel, paint, rust, curved surfaces, plastic layers, vibration, sideways loading, temperature changes or imperfect contact. These factors can dramatically reduce the actual holding force.

What coatings are available for neodymium magnets?

Common coatings include nickel-copper-nickel, zinc, epoxy, gold, copper, rubber, plastic and other special finishes. Nickel plating is common because it provides a durable metallic finish, while epoxy and rubber coatings can help in applications involving moisture, scratching or better grip. Coating choice should match the environment and the way the magnet will be handled.

Can magnet coatings prevent rust completely?

A coating can reduce corrosion risk, but it does not make every magnet permanently rustproof. If a coating is scratched, cracked or exposed to aggressive moisture, the magnet material underneath may corrode. For wet, marine or outdoor environments, use a suitable coated magnet, a housed assembly or a material with better corrosion resistance. SG Magnetics offers water-resistant magnets with epoxy coating as well as waterproof options such as magnets with rubber coating, plastic coating and fully encapsulated steel coatings. These can be found in SG Magnetics' waterproof magnets, diving magnets and steel encapsulated magnets section.

What coating should I choose if I have a nickel allergy?

Users with nickel allergies or metal sensitivities should avoid direct skin contact with nickel-plated magnets where possible. Consider epoxy-coated, rubber-coated, plastic-coated or other suitable alternatives, and use gloves when handling magnets for long periods. Stop handling the magnet if skin redness, itching or irritation occurs.

Can magnets be used in hot environments?

Some magnets can be used in hot environments, but the allowable temperature depends on the magnet material and grade. Standard neodymium magnets are sensitive to heat, while SmCo, AlNiCo, ferrite and high-temperature neodymium grades can handle higher temperatures in suitable designs. Always check the maximum operating temperature before using a magnet near ovens, motors, engines, heaters or outdoor heat exposure.

What happens if a magnet gets too hot?

If a magnet is heated beyond its safe operating range, it may permanently lose part of its strength. If it is heated to an even higher temperature near or above its Curie temperature, it can lose its magnetism completely. Heat damage may not be visible, so performance should be tested if overheating is suspected.

Can magnets survive cold temperatures?

Many permanent magnets perform well in cold environments, and some may even show stronger magnetic behavior at lower temperatures. However, coatings, adhesives, housings and surrounding materials may become brittle or change dimensions. The full assembly, not only the magnet material, should be checked for low-temperature use.

Magnet Shapes and Product Types

What are disc magnets used for?

Disc magnets are round flat magnets used in closures, crafts, displays, sensors, packaging, fixtures and general holding. They are easy to install into drilled holes or recesses when the diameter and thickness are suitable. The pull force increases with diameter, thickness, grade and good contact with steel.

What are cylinder magnets used for?

Cylinder magnets are longer round magnets that can provide deeper magnetic reach than very thin discs. They are often used in sensors, retrieval tools, experimental setups, fixtures and embedded products. Their length and magnetization direction should be chosen carefully for the intended magnetic field pattern.

What are block magnets used for?

Block magnets are rectangular magnets used where a flat, straight edge or larger contact area is useful. They are common in motors, linear sensors, clamps, separators, holding fixtures, displays and product assemblies. Their orientation and pole face matter, especially when installed into a design.

What are ring magnets used for?

Ring magnets have a central hole and are used for fastening, alignment, sensors, speakers, displays and assemblies that require a screw, rod or axle to pass through the magnet. Some rings are magnetized through the thickness, while others may be diametrically or radially magnetized. Always check the magnetization direction before ordering.

What are countersunk magnets?

Countersunk magnets have a beveled hole designed for a countersunk screw. They are used for mounting magnets to wood, plastic, aluminum, walls, fixtures and display panels. The screw head must fit properly, and the magnet should not be over-tightened because brittle magnets can crack.

What are pot magnets?

Pot magnets are magnets inside a steel cup or housing. The steel redirects the magnetic field toward the open face, improving holding force on suitable steel surfaces while reducing stray field from the back. Pot magnets are widely used for holding, mounting, fixtures, signs, hooks, threaded attachments and temporary positioning.

What is the difference between a bare magnet and a pot magnet?

A bare magnet produces a magnetic field on multiple sides, while a pot magnet uses a steel shell to concentrate the magnetic field at one working face. This can make a pot magnet much stronger when it is in direct contact with steel on the open face, but it also means the holding force is directional.

Standard pot magnets usually require direct contact with the target surface and may not be suitable for applications where an air gap or distance is present. For applications where there is a slight air gap, such as thick paint-coated surfaces, SG Magnetics offers selected pot magnets from our SGMM, SGNPA(X) and SGNFA(X) ranges that perform better than many regular pot magnets in the market.

The SGMM range and selected "X" models are carefully designed to provide higher shear force and improved magnetic reach, allowing the magnetism of these specially designed pot magnets to act through a slight distance before reaching the target surface. These are our top-of-the-line pot magnets and are commonly used for holding, magnet fishing and diving applications.

However, pot magnets are not automatically suitable for lifting or safety-critical use. Always check the product rating, application conditions and safety requirements before use.

What are hook magnets used for?

Hook magnets are usually pot magnets fitted with hooks for hanging lightweight items from suitable steel surfaces. They are popular for homes, offices, warehouses, workshops, events and displays. Their safe use depends on the surface, load direction, vibration and whether the hook is loaded vertically or sideways.

What are eyebolt magnets used for?

Eyebolt magnets combine a pot magnet with a lifting-style eye or attachment point, but that does not mean every eyebolt magnet is certified for lifting. Many are intended for holding, hanging, retrieving or temporary attachment only. Check whether the product is specifically rated and certified before using it with suspended loads.

What are fishing magnets and salvage magnets?

Fishing magnets and salvage magnets are heavy-duty magnetic assemblies used to recover ferrous metal objects from water or to create temporary magnetic attachment points in marine environments. They usually include a strong pot magnet and an eye bolt or handle. They should be used with suitable rope, gloves, safe techniques and awareness of local rules, water hazards and sharp recovered objects.

What are diving magnets?

Diving magnets or diver magnets are heavy-duty magnetic assemblies used to create temporary magnetic attachment points in marine environments. They are commonly used by commercial divers in varying sea conditions.

Where can I buy diving magnets?

You can buy diving magnets at SG Magnetics. We offer special pot magnets that are more suitable than standard pot magnet fixtures for marine and underwater environments. Our diving magnet collection is frequently used by commercial divers in Singapore and around the world. It includes models with plastic-coated bases or fully encapsulated magnets inside stainless steel housings for increased durability. These pot magnets also feature eyebolts for easy attachment, as well as handlebars or levers to allow easier placement and removal during use.

What are flexible magnetic strips and sheets used for?

Flexible magnetic strips and sheets are commonly used for labels, signs, fridge magnets, displays, shelving tags, warehouse markers and light-duty closures. They can often be cut to size with suitable tools, depending on thickness. They are not designed to replace strong hard magnets where high pull force is required.

What are rubber-coated magnets?

Rubber-coated magnets are usually magnetic assemblies covered with a protective rubber layer. The rubber can reduce scratching, improve grip and provide better protection in outdoor or delicate-surface applications. They are useful for vehicles, signs, mounting bases and applications where a bare metal pot magnet may damage the surface.

What are magnetic assemblies?

A magnetic assembly combines a magnet with another component such as a steel housing, hook, screw, channel, rubber coating, handle or bracket. Assemblies are designed to make the magnet easier to install, stronger in a certain direction or better protected. The assembly design can be just as important as the magnet material itself.

What are arc magnets and segment magnets used for?

Arc magnets are curved magnets commonly used in motors, generators, rotors and specialized magnetic assemblies. Their curved shape allows them to fit around a circular rotor or stator. Ordering arc magnets usually requires detailed dimensions, magnetization direction, material, grade and tolerance requirements.

What are diametrically magnetized magnets?

A diametrically magnetized magnet has its north and south poles on opposite curved sides rather than on the flat ends. This is common in some cylinder, disc and ring magnet applications involving sensors, rotation or coupling. It must be specified clearly because it behaves differently from a standard axially magnetized magnet.

Pull Force, Holding Force and Real-World Performance

How do I choose the correct pull force?

First decide how the magnet will be used: vertical holding, horizontal mounting, closure, sensor triggering, retrieval or temporary positioning. Then consider the real surface, load direction, safety factor and whether failure could cause injury or damage. Use published or estimated pull force only as a comparison guide and test the actual application before relying on it.

Why does a magnet slide more easily than it pulls off?

Pull force is usually measured by pulling the magnet directly away from steel, perpendicular to the contact face. On a vertical wall, the load may cause the magnet to slide, which depends heavily on friction. A magnet that has high direct pull force may support much less weight when the load acts downward and causes sliding.

Does stacking magnets make them stronger?

Stacking magnets can increase magnetic strength up to a point, especially when thin magnets are stacked to create a thicker magnet. However, the improvement is not unlimited, and after a certain thickness the extra magnets may add little benefit. In other words, the magnetic strength increases at a decreasing rate. A single larger magnet or a properly designed assembly may be more predictable. However, stacking remains a viable option if you require a certain specific size and only if your application allows for it.

If I use two magnets together, do I get double the pull force?

Not usually. Two magnets attracting each other or working together may increase holding force, but the result is not simply the sum of the two published pull force values. For stacking of two magnets, the force will not amount to double the force. For two magnets working together (e.g. side by side), the final force depends on geometry, pole alignment, contact area, distance, steel parts and the magnetic circuit.

Why does steel thickness matter?

A magnet needs enough steel to carry the magnetic flux. If the steel is too thin, it can become magnetically saturated and the magnet will not achieve its expected holding force. Thick, clean, flat mild steel usually gives better results than thin sheet metal, stainless steel, painted steel or rusty steel.

Why does paint or coating reduce magnet strength?

Paint, powder coating, plastic, tape, adhesive and rust create a gap between the magnet and the steel. Even a small gap can reduce holding force significantly, especially for small magnets. If maximum strength is needed, reduce the gap and use a clean, flat, ferromagnetic contact surface.

What is an air gap in magnet applications?

An air gap is any non-magnetic space between the magnet and the target, including actual air, plastic, paint, adhesive, cardboard, fabric or uneven contact. Air gaps weaken magnetic attraction quickly. When designing a magnetic closure or holder, minimizing the air gap is one of the best ways to improve performance.

Does a magnet work better on flat steel or curved steel?

Flat steel usually provides better contact and stronger holding than curved or uneven steel. A curved surface can reduce the contact area and create air gaps. For pipes, cylinders or curved structures, a magnet shaped for that surface or a custom fixture may perform better.

Can I rely on a magnet for safety-critical holding?

Do not rely on ordinary magnets for safety-critical holding, overhead loads, lifting, fall prevention, personal safety, vehicle safety or suspended loads unless the product is specifically designed, tested, certified and approved for that purpose. Add mechanical backup and consult a qualified professional where failure could cause harm or property damage. Magnets can release suddenly if the surface, angle, gap or load changes.

How do I test a magnet before using it in production?

Test the magnet in the same orientation, surface condition, temperature, vibration and load direction that it will experience in real use. Include safety factors and repeated tests, not just one perfect trial. For commercial or safety-related uses, document the test method and consult a competent engineer or safety professional.

Why do some magnets feel strong in the hand but weak in my application?

A magnet may feel strong when it snaps to a thick steel plate, but your application may involve thin steel, stainless steel, paint, plastic, movement, misalignment or a load pulling sideways. The magnet is not defective simply because the application reduces its performance. The design must match the magnet's working conditions.

What is the best magnet for holding through a gap?

Larger magnets, thicker magnets and certain magnetic assemblies may perform better through a gap, but the best choice depends on the distance and target material. For long gaps, a larger pole area can sometimes help more than simply increasing grade. For pot magnets, the design will also affect their performance through the gap. For instance, SG Magnetics' SGNPA (X), SGNFA (X) and SGMM series pot magnets offer better holding through a gap compared to common pot or fishing magnets in the market or our standard SGNPA or SGNFA models.

Safety, Handling and Storage

Are magnets dangerous?

Magnets are useful and safe when handled correctly, but strong magnets can be hazardous. Risks include pinched fingers, chipped fragments, eye injury, swallowing hazards, interference with medical devices and damage to electronics. The stronger and larger the magnet, the more care is required.

Why should magnets be kept away from children?

Small magnets can be a serious swallowing hazard, especially if more than one magnet is swallowed. Multiple magnets can attract through body tissue and cause severe internal injury. Keep strong or small magnets away from children and seek urgent medical help if ingestion is suspected.

Can magnets affect pacemakers or medical implants?

Yes. Magnetic fields can interfere with pacemakers, implanted defibrillators, hearing aids and other medical devices. Anyone with an implanted or wearable medical device should keep magnets at a safe distance and follow medical or device-manufacturer advice.

Can magnets damage phones, laptops or bank cards?

Strong magnets may affect magnetic stripe cards, sensors, watches, compasses, hard drives, speakers and some electronic devices. Modern phones and laptops are more resilient than older magnetic media, but strong magnets should still be kept away from sensitive electronics unless the application is understood. Avoid placing powerful neodymium magnets directly against devices or cards.

Why should I wear eye protection with strong magnets?

Neodymium, ferrite and samarium cobalt magnets can chip or shatter if they collide. Broken fragments may fly outward like projectiles and injure the face, skin or eyes. Wear safety goggles when handling strong, brittle or large magnets, especially during assembly, testing or separation.

How should I separate strong magnets safely?

Slide magnets apart rather than pulling them directly away from each other when possible. Use spacers, wood, plastic wedges or a table edge to control the movement. Keep fingers out of the pinch zone and separate large magnets one at a time.

Can magnets be cut, drilled or machined?

Most hard magnets should not be cut or drilled with normal tools. Neodymium, ferrite and SmCo magnets are hard and brittle, and machining can generate heat, dust and fragments. Holes, countersinks and custom shapes should normally be manufactured before magnetization or handled by specialist facilities. Soft magnets such as SG Magnetics flexible magnets can be cut to shape easily using a pair of scissors. Special magnets such as our neodymium flexible magnets (SG Magnetics' P grade, e.g. P2, P3 and P4 magnets) can also be cut using a pair of strong scissors.

How should magnets be stored?

Store magnets in a dry, clean place away from children, pets, electronics, pacemakers, high heat and loose steel objects. Use spacers, foam, cardboard or keeper plates to separate strong magnets. Label strong magnets clearly so users know they require careful handling.

What should I do with damaged magnets?

Stop using magnets that are cracked, chipped, corroded, swollen, loose in their housing or mechanically damaged. Wrap broken pieces before disposal to reduce cuts and uncontrolled attraction. Do not use damaged magnets for holding, mounting or recovery work where failure could cause injury or damage.

Can magnets catch fire?

Finished magnets do not normally catch fire during ordinary use, but machining dust from rare earth magnets can be flammable and must be controlled by specialists. Excessive heat can also damage magnets and coatings. Do not grind, weld, solder or overheat magnets unless the process has been professionally assessed.

Can I carry magnets in my pocket?

Small weak magnets may be harmless in a pocket, but strong magnets can pinch skin, damage cards, affect keys or attract metal objects. Keep strong magnets in protective packaging and away from phones, bank cards, watches and medical devices. Do not carry loose powerful magnets casually.

Are magnets safe for classrooms and experiments?

Magnets can be useful educational tools, but they must be selected for the age group and activity. Avoid small loose magnets for young children and provide supervision for stronger magnets. Use safety goggles and clear handling rules for experiments involving brittle magnets or magnetic collisions.

Using Magnets for Intended Purposes

Why should magnets only be used for their intended purpose?

Magnets should only be used within the limits stated in the product description, specification or safety guidance. A magnet sold for holding, mounting or display may not be suitable for lifting, overhead suspension, vehicle attachment, marine recovery or safety-critical use. Misuse can cause sudden release, falling objects, injury, property damage or failure of the application. Additionally, users should always follow local regulations.

Are published pull force values guaranteed in every application?

No. Pull force values are usually measured under controlled or ideal test conditions, such as a clean, flat, thick steel plate with direct contact and a straight pull. Real applications may include air gaps, rust, paint, thin steel, curved surfaces, vibration, moisture, heat and sideways loading. Treat pull force as a guide and test the actual application.

When should I consult an expert about magnet use?

Consult a qualified engineer, safety professional or other competent expert whenever magnet failure could cause injury, damage, falling loads, operational risk or legal compliance issues. This includes lifting, overhead holding, public installations, vehicles, workplace equipment, marine recovery and custom industrial fixtures. Professional assessment helps determine safety factors, mechanical backup and regulatory requirements.

Can ordinary pot magnets be used as lifting devices?

Ordinary pot magnets, hook magnets and eyebolt magnets should never be used as lifting devices unless they are specifically designed, tested, certified and clearly rated for lifting applications. Standard pot magnets are generally intended for holding, mounting, positioning or temporary attachment. In Singapore, workplace lifting equipment may be subject to MOM requirements, including applicable registration, inspection, testing and examination by an Authorised Examiner; users must ensure compliance before any lifting use.

Can I use magnets on vehicles?

Magnets used on vehicles must be selected carefully because vibration, wind, speed, curved panels, paint thickness, dirt, water and temperature can reduce holding force. Use rubber-coated magnets or purpose-designed assemblies where appropriate, and never rely on a magnet alone where detachment could endanger road users. Test under controlled conditions before use. In Singapore, always check with the relevant authorities, such as the LTA, to ensure your application is permitted before any fittings are installed.

Can I use magnets to hold signs?

Yes, magnets are commonly used for signs, labels and displays, but the magnet type must suit the surface and environment. Indoor signs may use flexible magnetic sheet, neodymium magnets or pot magnets, while outdoor signs need weather-resistant materials, secure attachment and consideration of wind loads. Check for sliding, vibration and surface damage. Always conduct your own tests in varying scenarios before actual application.

Can magnets be used for doors, cabinets or closures?

Yes, magnets are often used for cabinet doors, access panels, packaging, hidden closures and furniture. Choose a magnet that provides enough holding force without making the item difficult or unsafe to open. Consider air gaps, alignment, impact, corrosion and whether children can access small magnets.

Can magnets be used in food, medical or cleanroom applications?

Special environments require special assessment. Food, medical or cleanroom applications may require stainless housings, sealed assemblies, traceability, cleanability and material compliance. Do not assume a standard magnet is suitable for such use without checking the relevant requirements and regulations.

Applications by Industry and Everyday Use

What are common uses for magnets at home?

Home uses include fridge magnets, cabinet closures, cable management, tool holding, photo displays, curtain weights, door catches, removable hooks and organization. Choose magnets that are strong enough for the job but safe for the household environment. Keep small and strong magnets away from children and pets.

What are common uses for magnets in offices and schools?

Offices and schools use magnets for whiteboards, notice boards, classroom demonstrations, labels, fixtures, name tags, display panels and experiments. Flexible magnets and ferrite magnets are often suitable for light-duty use, while neodymium magnets may be used where compact strength is needed. Safety supervision is important for strong magnets.

What are common uses for magnets in warehouses?

Warehouses use magnets for shelf labels, rack labels, bin markers, document holders, temporary signs, tool organization and metal surface mounting. Flexible magnetic labels are popular because they can be moved without adhesive residue. Stronger pot magnets or magnetic hooks may be used where heavier items must be held, subject to safe limits.

What are magnets used for in manufacturing?

Manufacturing uses include jigs, fixtures, sensors, separators, assembly aids, motor parts, closures, robotic tooling, quality control and temporary holding. The magnet must be selected based on force, temperature, cycle time, surface condition and safety requirements. Custom magnetic assemblies may be better than off-the-shelf magnets for production processes.

What are magnets used for in electronics?

Magnets are used in speakers, headphones, microphones, motors, sensors, switches, hard drives, actuators and charging connectors. Electronics applications often require precise magnet size, field direction, coating and tolerance.

What are magnets used for in crafts and DIY projects?

DIY uses include hidden closures, model making, miniature bases, display cases, tool holders, picture frames and removable panels. Neodymium magnets are popular because small pieces can be very strong. Use the correct adhesive, avoid overheating (e.g. do not use hot glue) and keep magnets away from children.

What magnets are used for name badges?

Magnetic badge holders use small magnets or a magnetic backing plate to hold a name tag securely through clothing. They are commonly used for staff name badges, visitor passes, event badges, corporate uniforms and conference name tags because they help avoid pin holes, fabric damage and the need for sharp pins.

At SG Magnetics, we offer both magnetic badge holders and basic printing services for customised name tags. We also offer blank name tags that allow users to insert their own paper inserts, making it easy to personalise the badges.

SG Magnetics carries a range of magnetic badge holders, from standard magnetic name badge holders to extra-strong magnetic badges fitted with larger N52 grade magnets. We also offer specially designed magnetic badges featuring more magnets than a standard badge to provide greater holding force on thicker fabrics. Standard magnetic badge holders are suitable for shirts, blouses and light uniforms, while stronger holders are better suited for jackets, coats and thicker uniforms.

Customers looking for magnetic badge holders in Singapore can contact SG Magnetics for extra-strong name badge magnets for corporate, school, event and uniform applications.

Note: Magnetic badges should not be used by people with pacemakers or certain medical devices unless approved by a healthcare professional. They should also be kept away from magnetic stripe cards, watches and sensitive electronic devices.

What magnets are used for fishing and recovery?

Fishing and recovery magnets are usually strong pot magnet assemblies with eye bolts, handles or threaded attachments. They are designed to attract ferrous metal objects from water or hard-to-reach places. Use proper rope, gloves, safety awareness and local permission before magnet fishing or marine recovery work.

What magnets are used for signage?

Flexible magnetic sheets and strips are common for labels and light signs, while rubber-coated pot magnets can be used for heavier or temporary signs on steel surfaces. Outdoor signage must consider wind, rain, UV exposure, vibration and surface damage. Test before relying on magnets in public areas.

Which magnet should I use for educational purposes?

For most educational purposes, the best magnets are safe, easy to handle and suitable for the age group of the students. Neodymium, ferrite and AlNiCo magnets can all be suitable, depending on the topic being taught.

Different magnet shapes are used for different lessons. Horseshoe magnets, U-shaped magnets, bar magnets and ring magnets are commonly used in school science lessons because they are durable, easy to handle and simple to demonstrate. Neodymium magnets are much stronger, but they should only be used under proper adult supervision because they can pinch fingers, chip, crack or become dangerous if swallowed.

For young children, large plastic-cased magnets, educational AlNiCo magnets and educational ferrite magnets are usually better choices. For secondary school, junior college, polytechnic, university or laboratory demonstrations, stronger magnets such as neodymium magnets or specialised magnetic assemblies may be suitable.

SG Magnetics also offers:

Plastic-encased low-strength neodymium bar magnets suitable for primary school students.
Traditional AlNiCo educational magnets including AlNiCo 3 and AlNiCo 5 bar and horseshoe magnets.
Educational ferrite magnets for economical classroom use.

Adult supervision is always recommended.

What are the best magnets for school science experiments?

The best magnets depend on the lesson objective.

Bar magnets and horseshoe magnets demonstrate poles, attraction, repulsion and magnetic field lines.
Ring magnets demonstrate magnetic levitation and repulsion.
Ferrite disc or block magnets are ideal for general classroom demonstrations.
Magnetic wands help sort magnetic and non-magnetic materials.

For advanced experiments involving sensors, motors, generators or magnetic levitation, neodymium magnets may be suitable but require careful handling.

What magnets are safe for children to use?

Choose magnets that are large enough that they cannot be swallowed, easy to grip and not excessively strong. Large plastic-cased magnets, educational ferrite magnets and educational magnet sets are generally safer than small neodymium magnets. Always supervise children and avoid cracked, loose or sharp-edged magnets.

Are neodymium magnets suitable for education?

Yes, particularly for older students studying physics, engineering, robotics and sensors. However, because they are much stronger than ferrite magnets, they should only be used with proper supervision and safety instructions.

Are ferrite magnets good for classroom learning?

Yes. Ferrite magnets are affordable, suitable for basic magnetism lessons and easier for students to handle than neodymium magnets. However, they remain brittle and should be handled carefully.

What are AlNiCo magnets used for in education?

AlNiCo magnets are traditional classroom magnets used for demonstrating magnetic poles, field lines and compass behaviour. They are generally less brittle than many other magnet materials and are suitable for many school demonstrations. Supervision is still recommended.

What is the best magnet for teaching magnetic field lines?

Bar magnets and horseshoe magnets are among the best choices because their poles are easy to identify. Iron filings or magnetic viewing film can clearly show the magnetic field pattern.

SG Magnetics also supplies magnetic viewing film, iron filings, iron powder and ferrofluid for these demonstrations.

What magnets should I use for iron filings experiments?

Bar magnets and horseshoe magnets are the easiest for students to understand. Ferrite and AlNiCo magnets are often preferred because they are easier to manage than powerful neodymium magnets.

Always place paper or plastic between the magnet and iron filings for easier cleanup, and supervise all experiments.

What magnets are used for STEM projects?

STEM projects commonly use ferrite magnets, neodymium magnets, ring magnets, disc magnets, block magnets and magnetic strips. Choose the magnet based on the learning objective rather than simply selecting the strongest available.

What magnets are suitable for robotics and sensor education?

Small neodymium disc magnets, cylinder magnets and diametrically magnetized magnets are commonly used with Hall-effect sensors, reed switches, magnetic encoders and robotics projects. Ferrite magnets are suitable for beginner projects.

What magnets are best for making a simple electric motor?

Neodymium magnets are commonly used because they provide strong magnetic fields in compact sizes. Ferrite magnets can also be used for simple demonstrations. Students should keep magnets away from sensitive electronics.

What magnets are used to teach attraction and repulsion?

Bar magnets, horseshoe magnets, ring magnets and disc magnets are commonly used. Ring magnets are particularly popular because they can demonstrate magnetic levitation when mounted on a vertical rod.

What magnets are best for magnetic levitation demonstrations?

Ring magnets are ideal for simple levitation demonstrations using magnetic repulsion. More advanced levitation systems require electromagnets, electronic controls and stronger neodymium magnets. SG Magnetics also supplies levitating train experiment kits and levitation demonstration products.

Can magnets be used to teach magnetic and non-magnetic materials?

Yes. Students can test paper clips, coins, aluminium foil, copper, plastic, rubber, wood and glass to determine which materials are magnetic. Magnetic wands and ferrite magnets work well for these activities.

What magnet should teachers buy for a classroom magnet kit?

A classroom magnet kit may include:

Plastic-encased neodymium magnets
AlNiCo bar and horseshoe magnets
Ferrite disc and block magnets
Ring magnets
Magnetic viewing film
Iron filings
Compasses
Samples of magnetic and non-magnetic materials

The focus should be on safety, durability and ease of teaching.

What magnets are suitable for science centres, workshops and demonstrations?

Large bar magnets, horseshoe magnets, magnetic wands, ferrite blocks, ring magnets and magnetic viewing film are commonly used. Strong neodymium magnets should only be handled by trained instructors.

Are educational magnets suitable for preschool or kindergarten use?

Yes, provided they are large, enclosed and easy to grip. Small loose magnets, particularly neodymium magnets, should never be used with young children.

What safety precautions should schools take when using magnets?

Schools should use age-appropriate magnets, inspect them regularly, remove damaged magnets immediately, supervise students and keep strong magnets away from medical devices, electronic equipment and magnetic storage media.

Can students use magnets for home science projects?

Yes. Suitable projects include magnetic material testing, simple compasses, magnetic mazes, motors and field-line demonstrations. Parents should supervise children, especially when using strong magnets.

Where can I buy educational magnets in Singapore?

SG Magnetics supplies educational magnets for schools, teachers, students, STEM projects, science centres and home learning. Products include ferrite, AlNiCo, neodymium, magnetic sheets, magnetic strips, magnetic wands and magnetic viewing film.

What magnet should I use for a fridge magnet?

Small neodymium magnets, ferrite magnets or flexible rubber magnets are commonly used depending on the weight of the fridge magnet. Always consider the weight, contact area and fridge door material before selecting a magnet.

What magnet should I use for a glassboard?

Glassboards require much stronger magnets than standard whiteboards because the magnetic field must pass through glass. Strong neodymium glassboard magnets or purpose-built glassboard accessories are recommended.

What magnet should I buy for outdoor use in Singapore?

Rubber-coated magnets, plastic-coated magnets, epoxy-coated neodymium magnets, ferrite magnets or housed pot magnets are generally suitable for humid outdoor environments. Test for rain, UV exposure and vibration before use.

What magnet should I buy for a whiteboard or office board?

Small neodymium magnets are suitable for holding multiple sheets, while ferrite magnets provide an economical solution for everyday office use. Ensure the board has a magnetic steel backing.

What magnet should I buy for a warehouse rack label?

Flexible magnetic labels, magnetic strips and magnetic data card holders are ideal because they are easy to reposition without adhesive. SG Magnetics also offers printed magnetic barcode labels.

What magnet should I buy for a hidden cabinet closure?

Neodymium disc magnets, block magnets and countersunk magnets are commonly used. Pair them with a matching steel plate or another magnet and confirm the polarity before installation.

What magnet should I buy for magnet fishing?

Use a purpose-built fishing or recovery magnet together with a suitable eye bolt, rope and protective equipment. Never use loose or uncertified magnets for recovery work.

What magnet should I buy for high-temperature applications?

SmCo magnets, AlNiCo magnets, ferrite magnets and high-temperature neodymium grades are commonly used. The correct choice depends on the operating temperature and application.

What magnet supplier should I contact for Singapore magnet questions?

SG Magnetics can assist with neodymium, ferrite, AlNiCo, SmCo, flexible magnets, pot magnets, fishing magnets, diving magnets, magnetic labels and custom magnetic assemblies. They also support overseas shipping where permitted.

Installation, Adhesives and Fixing Methods

Can magnets be glued in place?

Yes, many magnets can be bonded using suitable adhesives such as two-part epoxy or industrial adhesives, depending on the surfaces. The bonding area should be clean, dry and free from oil or dust. Adhesive choice depends on the magnet coating, substrate material, temperature, load and whether impact or moisture is expected.

Why do magnets sometimes come loose from glue?

A magnet may come loose if the adhesive does not bond well to the coating, if the surface was dirty, if the pull force exceeds the bond strength, or if the magnet experiences shock, peel force, heat or moisture. Smooth nickel coatings can be difficult for some adhesives. Roughening the bonding surface may help, but avoid damaging the magnet coating unless corrosion risk is controlled. For specialized applications, such as bonding magnets to metal or magnets used on motors, other adhesives may be required.

Can I use super glue for magnets?

Super glue can work for small magnets in low-stress applications, but it may become brittle and may not handle shock, peel loads or moisture well. Epoxy is often a better option for stronger bonds. Always test the adhesive in the actual application before production use. For specialized applications, such as bonding magnets to metal or magnets used on motors, other adhesives may be required.

How should countersunk magnets be installed?

Use a screw that matches the countersink angle and does not force the magnet. Do not over-tighten, because the magnet can crack. If the magnet will experience impact or vibration, consider using a steel cup, retaining washer, adhesive support or a magnet assembly designed for mechanical fixing.

Should I use a steel backing plate with magnets?

A steel backing plate can improve magnetic performance by completing part of the magnetic circuit and providing a better attraction surface. It is often useful for magnetic closures, displays and fixtures. The steel must be thick enough and positioned correctly to be effective.

Can magnets be sewn into fabric?

It is possible, but they must be enclosed securely so they do not fall out. Some magnets are used in fabric closures, bags, garments or soft products. Special enclosed sewing magnets are usually safer than loose, brittle neodymium magnets. Consider washing, corrosion, nickel allergy and user access.

Can magnets be embedded in 3D prints?

Yes, magnets are often embedded in 3D printed parts for closures, tools and prototypes. Leave a tight pocket or recess, check pole orientation before inserting the magnet and use adhesive if needed. Keep heat from the printing and post-processing process within the magnet's safe temperature range. SG Magnetics can also provide basic 3D printing services with magnets attached or embedded.

How do I avoid installing magnets the wrong way around?

Mark the pole orientation before installation and test each magnet with a known reference magnet. For pairs that must attract, confirm the pole direction before gluing or pressing them into place. A simple installation jig can help prevent mistakes during repeated assembly

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Shipping, Overseas Delivery and Packing Magnets

Can magnets be shipped internationally?

Yes, magnets can often be shipped internationally when they are packed correctly and accepted by the courier or freight carrier. SG Magnetics can arrange overseas magnet shipping and worldwide magnet delivery where permitted, subject to product type, quantity, destination, packaging and applicable transport regulations. Strong magnets may need shielding and checks before air shipment.

Why do magnets sometimes come loose from glue?

Strong magnetic fields outside a package may interfere with aircraft instruments or attract ferrous materials during transport. For this reason, magnetized material may be regulated under air transport rules. Proper packaging reduces the external magnetic field and helps protect the parcel, carrier staff and other shipments.

What are the IATA magnetic field limits for magnetized material?

As a practical shipping guide, magnetized material is commonly assessed using external magnetic field measurements from the fully packed package.

If the field is below 0.002 gauss at 2.1 m (7 ft) from any surface, it is generally not treated as regulated magnetized material.
If it is 0.002 gauss or more at 2.1 m (7 ft) but below 0.00525 gauss at 4.5 m (15 ft), IATA and carrier requirements for UN 2807 Magnetized Material, Class 9 may apply.
If it exceeds 0.00525 gauss at 4.5 m (15 ft), it may not be accepted for air transport unless it is repacked, shielded and retested.

How should strong magnets be packed for shipping?

Strong magnets should be immobilized, separated and shielded. Use spacers, foam, cardboard, inner boxes and steel shielding where needed so the magnets cannot slam together or produce a strong external magnetic field. Loose magnets should not be placed unprotected in a parcel because they can break, damage packaging or attract metal objects.

Can I forward or export magnets myself after buying them?

Customers who repack, forward, export or ship magnets overseas are responsible for checking the latest IATA Dangerous Goods Regulations, courier restrictions, customs requirements, destination-country rules and documentation requirements. When in doubt, ask the courier, freight forwarder or a qualified dangerous goods professional before sending strong neodymium magnets, pot magnets, fishing magnets, diving magnets or large magnetic assemblies.

Do all magnets need dangerous goods paperwork?

No. Many small or properly shielded magnet shipments may fall below regulated field thresholds, but this depends on the packed parcel, not only on the magnet itself. Large quantities, strong neodymium magnets and magnetic assemblies are more likely to require additional attention. The safest approach is to test or confirm the shipment requirements before dispatch.

Buying Magnets, Custom Magnets and Specifications

How do I choose the right magnet size?

Choose the right magnet size by considering the available space, required holding force, surface contact area, safety factor and installation method. If you are replacing an existing magnet, measure the diameter, length, width, thickness, hole size and magnetization direction. If a specification sheet, data sheet or magnet grade is available, it will also be helpful for comparison.

If you are designing a new magnetic application, it is best to prototype with several magnet sizes and test them under real working conditions. Factors such as air gaps, paint, surface thickness, vibration, sliding force and temperature can significantly affect magnet performance.

Customers in Singapore may also bring their designs, objects or prototypes to SG Magnetics' physical shop to test with available magnet samples. SG Magnetics allows customers to test selected magnet samples in-store, making it easier to choose a suitable magnet size before purchase.

What information should I provide for a custom magnet?

Please provide the required size specifications, such as length, width, thickness, diameter, inner diameter, outer diameter or hole size. Drawings are preferred where available, especially for custom shapes or parts with critical dimensions.

Please also include any required tolerances, magnet material, magnet grade and other specifications, such as coating or plating, magnetization direction and operating temperature if you have specific requirements. If there are no such requirements, let us know and we will recommend a suitable option.

When available, a sample, photo, specification sheet or existing part number can also be helpful.

Lastly, please provide the required quantity and the date by which the magnets are needed.

What is magnetization direction and why does it matter?

Magnetization direction describes where the north and south poles are located. A disc magnet can be magnetized through its thickness or across its diameter, while a block magnet can be magnetized through its thickness, length or width. If the magnetization direction is incorrect, the magnet may not work as intended. SG Magnetics can also provide magnets with other magnetization methods, including radial magnetization.

What is tolerance in magnet manufacturing?

Tolerance is the acceptable dimensional variation from the stated size. Tight tolerances may be required for precision assemblies, press-fit parts, sensors or motor components. Standard stock magnets are usually suitable for general applications, but custom projects should specify all critical tolerances clearly.

Can magnets be customized?

Many magnets can be customized by material, grade, shape, size, coating, magnetization direction and assembly design, depending on quantity and manufacturing feasibility. Customization may involve tooling, longer lead times and minimum order quantities (MOQs). For urgent requirements, modifying the product design around a stock magnet may be faster and more economical.

What is MOQ for magnets?

MOQ stands for Minimum Order Quantity. Stock magnets can often be purchased in small quantities or even as single pieces, while custom magnets may require higher MOQs because of tooling, production setup, material preparation and magnetization fixtures. The MOQ depends on the magnet shape, material, coating, tolerance requirements and supplier capability.

At SG Magnetics, we offer flexible MOQ options even for customized magnets, although pricing will vary depending on the magnet specifications.

Can SG Magnetics help me choose a magnet?

SG Magnetics can help customers narrow down suitable magnet options based on the application, available space, surface material, quantity, operating environment and budget. However, the final choice should always be based on the customer's own requirements, testing results and application preferences.

For suitable applications, customers may also visit our shop to test selected sample magnets available in-store. This is helpful for checking how a magnet performs with an actual object, prototype or application before purchasing. Customers are encouraged to contact SG Magnetics before visiting so suitable sample magnets can be prepared where possible.

For safety-critical, lifting or regulated applications, customers should involve qualified professionals and comply with all applicable standards, testing requirements and local safety regulations.

Troubleshooting Magnet Problems

Why is my magnet not sticking strongly?

The most common reasons are unsuitable target material, thin steel, stainless steel, paint, rust, dirt, an air gap, a curved surface, a sliding load or a magnet that is too small for the job. Check whether the surface is ferromagnetic and whether the magnet is making full contact.

Why is my magnet not sticking to my fridge door?

A magnet may not stick to a fridge door if the door is made from non-magnetic stainless steel, aluminium, plastic, glass or another non-ferromagnetic material. Some modern refrigerators have stainless steel or coated doors that look metallic but are not magnetic, or are only weakly magnetic.

Another common reason is that the magnet is too weak for the surface. Thin paint, protective films, curved surfaces, thick coatings or uneven contact can also reduce the holding force. Flexible fridge magnets may work on some fridge doors but not others, especially if the steel layer behind the surface is thin or not magnetic.

To check, test the magnet on a known magnetic steel surface first. If it sticks strongly there but not on the fridge door, the issue is likely the fridge door material or coating rather than the magnet itself. For non-magnetic fridge doors, consider using adhesive hooks, suction holders or a separate magnetic board instead.

Why does my magnet stick to one side but not another?

Some assemblies, such as pot magnets, are designed to work mainly on one face. A bare magnet may also have poles on specific surfaces depending on its magnetization direction. Check the product type and pole orientation before assuming the magnet is defective.

Why do my magnets repel instead of attract?

Like poles repel, while opposite poles attract. If two magnets are installed with the same pole facing each other, they will push apart. Mark and test the polarity before gluing magnets into a product.

Why did my magnet crack?

Magnets can crack if they collide, are dropped, over-tightened, pressed unevenly, exposed to impact or machined incorrectly. Neodymium, ferrite and SmCo magnets are hard and brittle. Use spacers, controlled assembly methods and mechanical support to reduce impact.

Why did my neodymium magnet rust?

Neodymium magnets can corrode if their protective coating is damaged or if they are exposed to moisture, humidity, chemicals or outdoor environments. Once corrosion starts, the magnet may swell, flake or lose its integrity. Use better coatings, sealed housings or more corrosion-resistant materials for wet environments. SG Magnetics sells water-resistant and waterproof magnets—check with us for the available coating options.

Why did my magnet lose strength?

Possible causes include overheating, corrosion, physical damage, strong demagnetizing fields or unsuitable magnetic circuit conditions. Standard neodymium magnets are particularly sensitive to high temperatures. If strength loss is suspected, compare the magnet against a known good sample under the same test conditions.

Why does my magnet leave marks on a surface?

Metal magnet housings can scratch painted or polished surfaces, and trapped dirt between the magnet and the surface can cause marks. Rubber-coated magnets or protective films can reduce this risk. Always clean the surface before applying magnets to vehicles, appliances or finished metal.

Why does my hook magnet slide down a wall?

A hook magnet on a vertical steel wall is affected by sliding force and friction, not only by direct pull force. The published pull force is usually measured by pulling the magnet straight off a horizontal steel plate. Reduce the load, use a stronger or rubber-coated magnet, improve the surface or add mechanical support.

SG Magnetics carries rubber-coated magnetic hooks that are popular for household use. In Singapore, these rubber-coated hooks are commonly used on the doors of bomb shelters and home shelters in BTO and HDB flats.

Why does the same magnet perform differently on two surfaces?

Different surfaces may have different steel thicknesses, alloy compositions, coatings, rust, curvature, roughness or backing structures. Magnetic performance depends heavily on the target material. A magnet that works well on thick mild steel may perform poorly on thin stainless steel or painted sheet metal.

How do I know if a magnet is defective?

Test the magnet against a clean, flat, thick steel plate and compare it with an identical magnet if available. Check for cracks, coating damage, corrosion, incorrect size and incorrect magnetization. If the magnet performs normally on ideal steel but poorly in the intended application, the issue is likely the application conditions rather than the magnet itself.

Glossary and Technical Terms

What is Br or residual flux density?

Br is a material property that describes the magnetic induction remaining in a saturated magnetic material after the magnetizing field is removed. It is often listed in gauss or tesla. It should not be confused with the measured surface gauss on a finished magnet.

What is BHmax or maximum energy product?

BHmax is a measure of the maximum magnetic energy a material can provide under standard conditions. It is often used to compare magnet material grades. Higher BHmax usually means more magnetic energy from a given volume, but the finished magnet's performance still depends on its shape and application.

What is coercivity?

Coercivity describes how resistant a magnet material is to demagnetization. A material with higher coercivity is better able to resist external fields or challenging conditions that try to reduce its magnetization. It is important for motors, high-temperature use and repelling magnet arrangements.

What is max operating temperature?

Maximum operating temperature is the temperature at which a magnet may be exposed without significant long-term loss of magnetism.

What is Curie temperature?

Curie temperature is the temperature at which a magnetic material loses its ferromagnetic ordering. Heating a magnet near or above this temperature can destroy its magnetism. The practical maximum operating temperature is usually much lower than the Curie temperature.

What is axial magnetization?

Axial magnetization means the north and south poles are located on the flat ends of a disc, cylinder or ring magnet. It is common for many round magnets used in holding applications. The magnet attracts most strongly from the two flat faces.

What is diametric magnetization?

Diametric magnetization means the north and south poles are located on opposite curved sides of a round magnet. This type is used in certain sensor, encoder, coupling and rotating applications. It must be specified clearly because it behaves differently from axial magnetization.

What is a keeper?

A keeper is a piece of ferromagnetic material placed across the poles of a magnet to help preserve magnetization and reduce stray magnetic fields. Keepers are often used with AlNiCo magnets and some horseshoe magnets. They can also make storage safer by reducing external magnetic attraction.

What is magnetic shielding?

Magnetic shielding uses ferromagnetic materials such as steel to redirect magnetic flux rather than truly blocking it. Shielding can reduce external magnetic fields in certain directions and is important for packaging, sensors and nearby electronics. Its effectiveness depends on the material, thickness, geometry and magnetic field strength.