Flexible Magnets

General Introduction

Flexible Rubber magnets are compound materials made by mixing ferrite magnet powder and rubber. Pressing or rolling makes the finished flexible rubber magnet. Because the material has good plasticity, the finished flexible rubber magnets or semi-manufactured flexible rubber magnets can incise, stiletto, slit or back up other materials randomly, have good antisepsis and difficult demagnetization. The raw materials are plentiful, so the price is lower. Flexible Rubber magnet are natural Flexible Rubber magnetsor isomer Flexible Rubber magnets. Natural rubber magnets have weak magnetism, are used on iceboxes, presswork and marketing and promotion premiums. Isomer rubber magnets have strong magnetism, and are used in such applications as micro-motors and magnet toys.

  • Powerful:
    Supersaturated with magnetism in multiple pole patterns.
  • Durable:
    Easy to maintain. Permanent magnetism guaranteed.
  • Safe:
    Non-toxic, lead-and barium-free.
  • Wide temperature range:
    Withstands continuous exposure to temperatures from -40 degrees Fahrenheit to 160 degrees Fahrenheit without demagnetizing.

Flexible Magnet Basic Information:

  • Made from Strontium Ferrous Oxide, K-resin (rubber) and some other trace elements.
  • They are extruded, injected or calendared.
  • They are often used in signs, promotional / decorative magnets and door seal applications because of their low cost.
  • Custom sizes available in 3-4 weeks. Stock sizes and price list available upon request by.

Typical Magnetic properties of Flexible rubber magnet, Rubber Magnets

Material Iso / Anisotropic Remanence Coercive Force Intrinsic Coercive Force Max. Energy Product
Br Hcb Hcj (BH)max
mT Gs kA/m Oe kA/m Oe KJ/m3 MGOe
FRM-5 Isotropic 165+/-10 1,650+/-100 108+/-8 1,350+/-100 132+/-8 1,650+/-100 5.2+/-0.4 0.65+/-0.05
FRM-6 Isotropic 170+/-10 1,700+/-100 112+/-8 1,400+/-100 136+/-8 1,700+/-100 5.6+/-0.4 0.70+/-0.05
FRM-8 Semi-aniso 220+/-5 2,200+/-50 136+/-8 1,700+/-100 160+/-8 2,000+/-100 8.0+/-0.4 1.00+/-0.05
FRM-11 Anisotropic 245+/-5 2,450+/-50 140+/-8 1,750+/-100 148+/-8 1,850+/-100 11.2+/-0.4 1.40+/-0.05
FRM-12 Anisotropic 247.5+/-2.5 2,475+/-25 168+/-8 2,100+/-100 224+/-8 2,800+/-100 12.0+/-0.4 1.50+/-0.05


Manufacturing Methods

Extrusion: to produce materials in strip form (from about 1/4″ to 10″ wide)
Calendering: to produce materials in sheet form (up to about 24″ wide)

For both methods, the first step is to form a “compound”, which is a wet slurry of powder in the binder material.

Extrusion involves squeezing heated compound through a shaped die, cooling the shaped material as it exits the die, and magnetizing the material. The standard grade materials are only magnetic on one side.

Calendering involves squeezing the compound between rollers to compress and flatten it to form a sheet. The sheet is fed through sets of rollers several times until it reaches the desired thickness. It is then slit to the desired width and magnetized. The standard grade materials are only magnetic on one side.

Shapes, Sizes, and Grades AvailableStandard stocked shapes include strip and sheet in the lower energy grades, strip and a variety of punched parts in ring, disc, and bar shapes in the higher energy grades. Non-standard shapes and sizes can be fabricated to blueprint specifications from raw stock. Non-standard profiles of the 0.6 MGOe material can be extruded by fabricating special dies.

Surface TreatmentsNo surface treatments are required to protect against corrosion. We are able to laminate a variety of decorative facings to magnetic strip.

MachiningFlexible materials are relatively easy to fabricate: they may be cut, scored, punched, slit, or die cut to shape. We are equipped to fabricate these materials to specification.

Magnetizing and HandlingLow energy flexible magnets are magnetized with multiple poles on one surface to give greater holding force. Higher energy flexible magnets are magnetized either multiple pole, or single pole on one surface. No special handling precautions have to be taken with flexible magnets since they are relatively weak magnetically, and are not brittle.

Temperature EffectsMagnetic properties of flexible magnets degrade linearly with temperature in the same way as Ceramic magnets. However, the limiting factor for flexible magnets are the binder materials used to render them flexible: these begin to flow at temperatures of about 250F.

Common Applications for Flexible MagnetsFlexible magnets are used in a variety of applications from labeling, holding, door gaskets, and signs, to micromotors and CRT focusing. Typical applications: crafts, toys, games, magnetic signs, displays, production control (or visual aid) systems, warehouse shelf labeling, door gaskets, door and cabinet closures, small tool and instrument holders, movable markers, advertising premiums, magnetic business cards, architectural planning layouts, etc.