Bearing size chart 6000 to 6310: bore, OD, width, and a reverse lookup (I measured 17 x 40 x 12, which bearing is it?)

October 6, 2026

A 6203 bearing is 17 mm bore x 40 mm outside diameter x 12 mm wide. In a 60, 62 or 63 series number, the last two digits give the bore: 00 = 10 mm, 01 = 12, 02 = 15, 03 = 17, then from 04 multiply by 5. We sell the 6203-2RS in packs of 10.

If you only needed the 6203, you can stop here. Every size from 6000 to 6310, plus 608, is in the table below, and the reverse lookup further down goes from your measurements to the number.

6000 to 6310 bearing size chart (mm)

Bearing	Bore (mm)	OD (mm)	Width (mm)	2RS, pack of 10	ZZ, pack of 10	2RS, packs of 2, 3 or 5
6000	10	26	8	Yes	Yes	No
6001	12	28	8	Yes	Yes	No
6002	15	32	9	Yes	Yes	No
6003	17	35	10	Yes	Yes	No
6004	20	42	12	Yes	Yes	No
6005	25	47	12	Yes	Yes	Yes
6006	30	55	13	Yes	Yes	Yes
6007	35	62	14	Yes	No	Yes
6008	40	68	15	Yes	No	Yes
6009	45	75	16	Yes	No	Yes
6010	50	80	16	Yes	No	Yes
6200	10	30	9	Yes	Yes	No
6201	12	32	10	Yes	Yes	No
6202	15	35	11	Yes	Yes	No
6203	17	40	12	Yes	Yes	No
6204	20	47	14	Yes	Yes	No
6205	25	52	15	Yes	Yes	Yes
6206	30	62	16	Yes	Yes	Yes
6207	35	72	17	Yes	No	Yes
6208	40	80	18	Yes	No	Yes
6209	45	85	19	Yes	No	Yes
6210	50	90	20	Yes	No	Yes
6300	10	35	11	Yes	Yes	No
6301	12	37	12	Yes	Yes	No
6302	15	42	13	Yes	Yes	No
6303	17	47	14	Yes	Yes	No
6304	20	52	15	Yes	Yes	No
6305	25	62	17	Yes	Yes	Yes
6306	30	72	19	Yes	Yes	Yes
6307	35	80	21	Yes	No	Yes
6308	40	90	23	Yes	No	Yes
6309	45	100	25	Yes	No	Yes
6310	50	110	27	Yes	No	Yes
608	8	22	7	608-RS: Yes	608-ZZ: Yes	No

Source: bearing makers' published dimension tables (see Sources), read 28 September 2026. All 33 sizes from 6000 to 6310 were cross-checked between two makers' catalogues: every bore, OD and width agrees. The last three columns are from our product listings, 28 September 2026.

OD and width alone can point to two different bearings

Most people measure the outside and the width first, because that's what they can see. In this range, three pairs share the same outside diameter and width exactly:

35 x 11 mm is a 6202 (15 mm bore) or a 6300 (10 mm bore).
47 x 14 mm is a 6204 (20 mm bore) or a 6303 (17 mm bore).
52 x 15 mm is a 6205 (25 mm bore) or a 6304 (20 mm bore).

The bore alone doesn't settle it either. A 25 mm bore is a 6005, 6205 or 6305, depending on how big the outer ring is. So measure all three.

The second catch is the bore that fits no row. No standard 60, 62 or 63 bearing has a 16 mm bore, yet "16 x 35" is a common search. That's a special bore bearing: a standard outer ring (here a 6202, 35 x 11) with a different bore. We list several: 16 mm, 1/2" and 5/8" bores on both 6202 and 6203 rings, 3/4" on a 6203, 1/2" on a 6201 and 1" (25.4 mm) on a 6205. If your bore measures 12.7, 15.9, 16, 19.05 or 25.4 mm and the OD matches a 6201, 6202, 6203 or 6205, you have one of these.

How to read a 6000, 6200 or 6300 bearing number

The first digit, 6, means a deep groove ball bearing.
The second digit is the diameter series: 0, 2 or 3. For the same bore, a 63 has a bigger and wider outer ring than a 62, and a 62 is bigger than a 60. That's the difference between a 6205 (25 x 52 x 15) and a 6305 (25 x 62 x 17): same shaft, different housing.
The last two digits are the bore code: 00 = 10 mm, 01 = 12, 02 = 15, 03 = 17. From 04 up, multiply by 5, so 6204 = 20 mm and 6310 = 50 mm. A single last digit is the bore itself, so a 608 has an 8 mm bore.
Letters after the number (2RS, ZZ) are the seals or shields. They don't change the size. Bearing makers list the shielded and sealed versions on the same dimension row as the open bearing.

These boundary dimensions are standardised by ISO, which is why a 6203 from one maker has the same bore, OD and width as a 6203 from another.

Reverse lookup: I measured it, which bearing is it?

Measure the bore (the hole) with vernier callipers. Write it down to one decimal place, so you can tell 16 mm from 15.9 mm (5/8").
Measure the outside diameter across the outer ring.
Measure the width of the outer ring.
Find your bore in the left column below, then match the OD x width.

Bore (mm)	60 series (OD x width)	62 series (OD x width)	63 series (OD x width)
8	22 x 7 = 608	not in this chart	not in this chart
9	24 x 7 = 609	not in this chart	not in this chart
10	26 x 8 = 6000	30 x 9 = 6200	35 x 11 = 6300
12	28 x 8 = 6001	32 x 10 = 6201	37 x 12 = 6301
15	32 x 9 = 6002	35 x 11 = 6202	42 x 13 = 6302
17	35 x 10 = 6003	40 x 12 = 6203	47 x 14 = 6303
20	42 x 12 = 6004	47 x 14 = 6204	52 x 15 = 6304
25	47 x 12 = 6005	52 x 15 = 6205	62 x 17 = 6305
30	55 x 13 = 6006	62 x 16 = 6206	72 x 19 = 6306
35	62 x 14 = 6007	72 x 17 = 6207	80 x 21 = 6307
40	68 x 15 = 6008	80 x 18 = 6208	90 x 23 = 6308
45	75 x 16 = 6009	85 x 19 = 6209	100 x 25 = 6309
50	80 x 16 = 6010	90 x 20 = 6210	110 x 27 = 6310

Source: bearing makers' published dimension tables (see Sources), read 28 September 2026.

The ones people search for most:

17 x 40 x 12 is a 6203.
8 x 22 (7 mm wide) is a 608.
9 x 24 (7 mm wide) is a 609. We sell it as a 10-pack of 609-ZZ.
15 x 35 (11 mm wide) is a 6202.
16 ID x 35 OD (11 mm wide) isn't a standard size. It's a 6202-16 special bore, 16 x 35 x 11 in our listing.
25 x 52 with a wide inner ring and grub screws is not a 6205 but a UC205 insert bearing. See our UCP204 to UCP206 pillow block dimensions.

If nothing matches, tell us the three measurements and what the bearing came out of before you order.

Which BES product fits

Pick the 10x 6000 to 6310 2RS bearings for any of the 33 sizes in the chart with rubber seals. Choose the size from the drop-down.
Pick the 10x 6000 to 6306 ZZ bearings if you want metal shields instead. ZZ is listed for 6000 to 6006, 6200 to 6206 and 6300 to 6306.
Pick the 2-pack, 3-pack or 5-pack if you need only a few of the larger 2RS sizes: 6005 to 6010, 6205 to 6210 or 6305 to 6310.
Pick the 10x 608-RS or 10x 608-ZZ for 8 x 22 x 7.
Pick the 6202-16 if your 6202-sized bearing has a 16 mm bore.

Browse every size, including the imperial bores, in ball bearings.

Questions people also ask

What are the 6204 bearing dimensions?

A 6204 is 20 mm bore x 47 mm OD x 14 mm wide. A 6303 has the same OD and width but a 17 mm bore, so check the bore.

What size is a 6205 bearing?

25 mm bore x 52 mm OD x 15 mm wide. The heavier 6305 has the same 25 mm bore but is 62 mm OD and 17 mm wide.

What are the 6201 bearing dimensions?

A 6201 is 12 mm bore x 32 mm OD x 10 mm wide.

What are the 6000 bearing dimensions?

A 6000 is 10 mm bore x 26 mm OD x 8 mm wide, the smallest size in this chart.

Is a 6203-2RS the same size as a 6203-ZZ?

Yes. Both are 17 x 40 x 12 mm. The suffix only says whether the sides are rubber seals (2RS) or metal shields (ZZ).

What are the 608 bearing dimensions?

A 608 is 8 mm bore x 22 mm OD x 7 mm wide, the same in the 608-RS and 608-ZZ.

Sources

NTN, Ball and Roller Bearings, Cat. No. 2203/E: Deep Groove Ball Bearings, dimension tables pp. B-22 to B-27 (ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf), read 28 September 2026.
NTN, Ball and Roller Bearings, Cat. No. 2203/E: Miniature and Small Size Ball Bearings, pp. B-50 to B-51 (ntnglobal.com/en/products/catalog/pdf/2203E_b03.pdf), read 28 September 2026.
NTN, Ball and Roller Bearings, Cat. No. 2203/E: Boundary Dimensions and Bearing Number Codes, pp. A-48 to A-51 (ntnglobal.com/en/products/catalog/pdf/2203E_a05.pdf), read 28 September 2026.
NSK, Deep Groove Ball Bearings (nsk.com/content/dam/nsk/am/en_us/documents/bearings-americas/Deep-Groove-Ball-Bearings.pdf), dimension tables, read 28 September 2026.

Checked against the NTN and NSK catalogues and our product listings on 28 September 2026.