1.  Characteristics of Various of Bearings

2.  Material

- The rings, balls, needles and rollers of MVB bearings can be made of refining bearing steel AISI52100, stainless steel AISI440C, AISI420, etc.

- Cages are normally punch-pressed from brass strips H62 or steel strips 08, SPCC BQB402, as well as stainless steel strips AISI304, AISI302, fiber reinforced phenolic resin, plastics or copper stock, etc;

- The shields can be made of Japanese SPCC JISG3141 or stainless steel AISI304 or AISI302.

- Seals: synthetic rubber hot pressed with phosphatizing steel (AISI304 or AISI302 may used for stainless steel bearings) skeleton

The chemical composition of bearing steel and stainless steel are listed as follows:

Steel No.	c%	Si%	Mn%	S%	P%	Cr%
AISI52100	0.95-1.05	0.15-0.3	0.25-0.45	<0.025	<0.025	1.3-1.6
AISI440C	0.90-1.05	<0.8	<0.8	<0.04	<0.03	16-19

Country	China	ISO	U.S.A	Germany	Japan	Sweden
Bearing Steel No.	GCr15	683/XVII1	(AISI)52100	(Din)100Cr6	(Jis)SVJ2	SKF3

3.  Bearing Precision Grade

Standards	Precision Grade
GB	G	E	D	C	B
ISO	Normal Class	Class6	Class5	Class4	Class2
ANSI	ABEC-1	ABEC-3	ABEC-5	ABEC-7	BEC-9
DIN	P0	P6	P5	P4	P2
JIS	0	6	5	4	2

4.  Rolling Bearing's Tolerance

Precision of radial bearings (excepting taper roller bearings)

Precision of taper roller bearings

Precision of thrust ball bearings

Precision of conic bore radial bearings

5.  Deep Groove Ball Bearing's Vibration and Noise Class

The vibration and noise of deep groove ball bearings are normally classified as Z1, Z2(higher class than Z1), and Z3 (highest class). It is usually measured by instrument of SO910-1. While for bearings used for electric motors, the vibration & noise is measured by BVT-1 and classified as EMQ ZV1, ZV2 and ZV3. Customer needs to mark the requirement of vibration and noise class in order.

Bearing Vibration speed Grade can not be over the following Values(dB)

Bore Diameter (mm)	Diameter Series		Diameter Series			Diameter Series
	Z1	Z2	Z1	Z2	Z3	Z1	Z2	Z3
4	34	32	35	32	30	36	33	31
5	36	34	37	34	32	37	35	33
6	36	34	37	34	32	37	35	33
7	38	35	38	36	34	--	--	--
8	38	35	38	36	34	--	--	--
9	40	36	40	37	35	--	--	--
10	42	38	42	39	35	44	40	37
12	43	39	43	39	35	45	40	37
15	44	40	44	41	36	46	42	38
17	44	40	45	41	36	47	42	38
20	45	41	46	42	38	48	43	39

Single Bearing Vibration Speed Grade Allowed The Limit Value(um/s)

Bore Diameter d mm	V1			V2			V3
	Low Frequency	Medium Frequency	High Frequency	Low Frequency	Medium Frequency	High Frequency	Low Frequency	Medium Frequency	High Frequency
5	90	60	50	58	36	30	35	21	18
6	90	60	50	58	36	30	35	21	18
7	110	80	65	72	48	40	44	28	24
8	110	80	65	72	48	40	44	28	24
9	110	80	65	72	48	40	44	28	24
10	140	100	85	90	60	50	55	35	30
12	140	100	85	90	60	50	55	35	30
15	180	130	100	110	78	60	65	46	35
17	180	130	100	110	78	60	65	46	35
20	220	160	125	130	100	75	80	60	45
22	220	160	125	130	100	75	80	60	45
25	220	160	125	130	100	75	80	60	45

6.  Bearing's Internal Radial Clearance of ...

Deep Groove Ball Bearings

Matched Angular Contact Ball Bearings

Double Row Angular Contact Ball Bearings

Self-aligning Ball Bearings

Electrical Motor Bearings

Cylindrical Roller Bearings Needle Roller Bearings

Spherical Roller Bearings

7.  ISO1132/GB4199 Bearing Tolerance Symbols Definitions

8.  Characteristics of grease lubrication

9.  inch-mm conversion table