What is soft rubber magnet? What is the difference between the grades of soft rubber magnets?

Answer
The soft rubber magnet material is mainly made of ferrite magnetic powder mixed with rubber raw materials, so it has the magnetic force of the magnet and the softness of the rubber, the surface is wear-resistant and scratch resistant, and it is easy to roll up and store, so it is widely used in magnetic advertising products and educational supplies.

In terms of grade, it can be divided into two categories: equal squareness (RM1) and different squareness (RM2). Under the same size, the different squareness is stronger than the equal squareness, and the equal squareness is usually magnetized by one side multipole magnetization (one side has magnetic force), while the different squareness can be magnetized not only by one side multipole magnetization (two sides have magnetic force, one side is strong and one side is weak), but also by thickness magnetization (one side one pole).

The following table shows the magneto pneumatic characteristics of soft rubber magnets:

Characteristic	Residual magnetic beam density		Magnetic retention		Internal magnetic force		Maximum magnetic energy product		Remarks
	Br		bHc		iHc		(BH)max
Grade	Gauss	mT	Oe	KA/m	Oe	KA/m	MGOe	KJ/m3
RM-11	1600	160	1250	100	2100	167	0.63	5	Isotropy
RM-12	1500	150	1150	92	2400	191	0.45	3.6	Isotropy
RM-13	1600	160	1200	96	1500	119	0.6	4.7	Isotropy
RM-21	2600	260	2300	183	2880	230	1.6	12.6	Heterogeneity
RM-22	2450	245	2200	175	2600	207	1.4	11.1	Heterogeneity
RM-23	2400	240	2000	159	2400	191	1.35	10.7	Heterogeneity

The following are the physical properties of soft rubber magnets:

Characteristic	Isotropy	Heterogeneity
Working temperature	-5 ℃ ~ +80 ℃	-40 ℃ ~ +100 ℃
Density	3.60~4.00 g/cm3	3.50~3.70 g/cm3
Tensile strength	20~100 Kg/cm3	75~90 Kg/cm3
Hardness	50~54 Hv	30~45 Shore D