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.

Buyer FAQ

Questions buyers ask before choosing the next bearing option

What is the main takeaway from Bearing Knowledge?

The main takeaway is that bearing knowledge should be checked against the bearing family, dimensions, load direction, speed, and operating conditions instead of relying on the title or size alone.

When should I use this guide before requesting a quote?

Use the guide when you are comparing bearing models, checking suffix meanings, confirming seal or clearance choices, planning maintenance, or preparing details for replacement, production, or OEM sourcing.

How does this topic connect to bearing supply?

The topic supports the Bearing Supply decision path by helping buyers understand fit, performance, specification details, or maintenance factors before choosing a product page or contacting the team.

Can this guide replace a final specification check?

No. The guide helps prepare the decision, but a final check should still confirm the part number, dimensions, load, speed, seal, clearance, precision, application, and order quantity.

What should I send if I need help after reading this guide?

Send the bearing number, measured size, photos if available, application, quantity, and any special operating conditions. That gives the team enough context to recommend the right product family or quote route.

Need help checking fit, price, or lead time? Request a bearing quote

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