Bearing Knowledge

Posted by admin

2020-08-12

On 2020-08-12

Bearing knowledge include bearing inner diamater calculation, bearing precision and internal clearance.

Bearing Inner Diameter：

ID（mm）	ID Code（mm）	For Example
10	0	6201 Bearing, 01 stands for bearing ID is 12mm
12	1
15	2
17	3
20~480	Bearing ID= ID Code*5	6205 Bearing , 05 standars for bearing ID is 25mm

Bearing Knowledge- Bearing Precision：

Bearing precision, in other words dimensional accuracy and rotation accuracy, has corresponding international standards and national standards.
National standards for different countries are consistent with international standard.

Country	Standard	Precision
China	GB/T307.1	P0	P6	P5	P4	P2
USA	ANSI/AFBMA Std.20	ABEC-1	ABEC-3	ABEC-5	ABEC-7	ABEC-9
Japan	JIS B 1514	0	6	5	4	2
Germany	DIN 620	P0	P6	P5	P4	P2
International	ISO 492	Class 0	Class 6	Class5	Class4	Class2

Internal Clearance:

Internal bearing clearance refers to the amount of radial or axial displacement when either the inner ring or the outer ring is fixed, and the unfixed one is moved. Depending on the direction of movement, it can be divided into radial clearance and axial clearance.
Generally we control the radial clearance for deep groove ball bearings , while we control axial clearance for double row angular contact ball bearings.

For deep groove ball bearings, radial clearance is as below,

Bearing ID(mm)		C2		C0		C3		C4		C5
＞	≤	min	max	min	max	min	max	min	max	min	max
2.5	10	0	7	2	13	8	23	14	29	20	37
10	18	0	9	3	18	11	25	18	33	25	45
18	24	0	10	5	20	13	28	20	36	28	48
24	30	1	11	5	20	13	28	23	41	30	53
30	40	1	11	6	20	15	33	28	46	40	64
40	50	1	11	6	23	18	36	30	51	45	73
50	65	1	15	8	28	23	43	38	61	55	90
65	80	1	15	10	30	25	51	46	71	65	105
80	100	1	18	12	36	30	58	53	84	75	120

For double row angular contact ball bearings, axial clearance is as below,

Bearing ID (mm)		C2		C0		C3
＞	≤	min	max	min	max	min	max
—	10	1	11	5	21	12	28
10	18	1	12	6	23	13	31
18	24	2	14	7	25	16	24
24	30	2	15	8	27	18	37
30	40	2	16	8	29	21	40
40	50	2	18	11	33	23	44
50	65	3	22	13	36	26	48
65	80	3	24	15	40	30	54
80	100	3	26	18	46	35	63

If you have any questions or suggestion about the bearing knowledge that we shared, just leave a comment and we will give you reply within 12 hours !

Questions that usually come up after Bearing Knowledge

Which next options usually help after reviewing Bearing Knowledge?

Most buyers benefit from one broader family destination, one more commercial route, and one supporting guide that answers the next practical question. That combination usually turns research into a clearer shortlist.

Why add related bearing destinations beside Bearing Knowledge?

Because the first answer often leads to a second question about fit, applications, supplier choice, or repeat-order confidence. Keeping those next destinations close reduces unnecessary backtracking.

When is it worth moving from reading into a quote or product review?

That move usually makes sense once the topic has narrowed the likely bearing family and the remaining unknowns are commercial, dimensional, or application-specific rather than purely educational.

What usually makes the next bearing decision easier after Bearing Knowledge?

The process is often easier when the wider family view, the more commercial destination, and one practical guide stay visible together. That keeps the decision grounded in both application detail and buying reality.

Blog