A 608 bearing is 8 mm bore x 22 mm outside diameter x 7 mm wide, and the 608ZZ (two metal shields) and 608-2RS (two rubber seals) are exactly the same size. We sell 10x 608-ZZ shielded ball bearings, 10x 608-RS rubber sealed bearings and an 8-pack of Japanese-made ITJ 608-ZZ skate bearings.
If you only needed the size, you can stop here. Below: which to pick, the lookalike numbers, and skate wheels.
608 bearing dimensions and specs
| Spec | 608 (all versions) |
|---|---|
| Bore (d) | 8 mm |
| Outside diameter (D) | 22 mm |
| Width (B) | 7 mm, open, shielded or sealed |
| Type | Single row deep groove ball bearing |
| Balls (one maker's design) | 7 balls of 3.969 mm |
| Mass (reference) | 12 g |
Source: bearing makers' published tables and 608 product pages (see Sources), read 2 October 2026.
Many small sealed and shielded bearings are 1 to 2 mm wider than the open version. The 608 isn't one of them: the makers' tables give 7 mm for the open and the shielded width.
608ZZ vs 608RS (608-2RS): which should I buy?
Pick the 608ZZ for the lowest drag where the bearing stays fairly dry and clean. Pick a contact-sealed 608-2RS where dust and water get at it. Both fit the same shaft and hole.
| 608ZZ (metal shields) | 608-2RS (rubber contact seals) | |
|---|---|---|
| Each side | A metal shield fixed to the outer ring, with a small gap at the inner ring | A rubber seal on a steel plate, its edge touching the inner ring |
| Torque (drag) | Small | Higher |
| Dust proofing | Good | Excellent |
| Water proofing | Poor | Very good |
| High speed | Same as an open bearing | Limited by the contact seals |
| Limiting speed, grease (one maker's rating) | 34,000 rpm | 23,000 rpm |
| Size | 8 x 22 x 7 mm | 8 x 22 x 7 mm |
Source: bearing makers' published seal comparison table (their ratings for their own shield and contact seal types) and 608 product pages (see Sources), read 2 October 2026.
Not every rubber seal touches the inner ring. NSK, for example, makes the 608 with a rubber non-contact seal (608VV) and with a rubber contact seal (608DD), and lists the contact version at a lower limiting speed with grease: 28,000 rpm against 34,000 rpm for its shielded 608ZZ1. On its 608s it writes DD and ZZ1; on its larger bearings, DDU and ZZ. Makers write these codes differently; our bearing seal codes guide has the full table.
The numbers that look like a 608 but aren't
On a 608 the seal or shield code doesn't change the size, but these codes and numbers often get mixed up:
- 608Z is one shield, with the other side open. Bearing tables list the 608Z (single shield) next to the 608ZZ (double shield), both 8 x 22 x 7. Our shielded listings are 608-ZZ.
- 608RS or 608-2RS? In Koyo's code, RS is one rubber seal and 2RS is two, just as Z is one shield and ZZ is two. Not everyone writes it that way, so look at both sides.
- 60822 isn't a standard number. In our reading it's a 608ZZ with the Zs taken for 2s, or a 608-2Z (the two-shield code) typed without the dash: either way, a double-shielded 608. Don't confuse it with a 60/22, which is a different bearing with a 22 mm bore (22 x 44 x 12).
- 627 has the same 22 mm outside and 7 mm width as a 608, but a 7 mm bore. Measure the bore.
- Other 8 mm bores: the 698 is 8 x 19 x 6 and the 628 is 8 x 24 x 8.
- 609 is 9 x 24 x 7, the next size up, in our bearing size chart.
How to identify the 608 you're replacing
- Read the number on the shield or seal face, if it's still legible.
- Look at both sides. Metal or rubber? On one side or both?
- Measure the bore, outside diameter and width with vernier callipers.
- Match the size against the table and the lookalikes above.
- Buy the same side protection that came out, unless you want to swap drag for sealing (see the table above).
608 bearings in skateboards, roller skates and scooters
Our ITJ 608-ZZ pack is listed for standard skateboard and roller skate wheels. It's 8 x 22 x 7 like any 608, and ITJ bearings are made in Japan. For a scooter, don't assume: pull one bearing out and measure it. If it's 8 x 22 x 7, it's a 608.
Some 608s are labelled with an ABEC number: the American Bearing Manufacturers Association's (ABMA's) tolerance classes for ball bearings, ABEC-1 to ABEC-9. Bearing makers compare them with ISO's classes, and the values differ slightly between standards. Our 608 listings don't state an ABEC class.
Which BES 608 fits
- Pick the 10x 608-ZZ shielded ball bearings if the old bearing had metal shields, or you want the lower drag of a shield.
- Pick the 10x 608-RS rubber sealed bearings if you want rubber seals. The listing says they keep out dust and other impurities but doesn't say whether the seals are contact or non-contact; if water resistance matters, ask us before ordering.
- Pick the 8x ITJ 608-ZZ skateboard and roller skate bearings for skate wheels, or if you want a Japanese-made 608.
- Pick the 10x 604RS to 609RS and 626RS sealed bearings if you need other small sealed sizes in the same order. Choose 608RS from the drop-down.
More sizes, including the 6000 to 6310 range, are in ball bearings.
Questions people also ask
What are the 608ZZ bearing dimensions?
8 mm bore x 22 mm outside diameter x 7 mm wide, the same as the open 608 and the 608RS (608-2RS).
What does ZZ mean on a 608 bearing?
A metal shield on both sides. A single Z is one shield.
Is 608RS the same as 608-2RS?
They're the same size, 8 x 22 x 7. Whether "RS" means one seal or two depends on who wrote it, so look at both sides. Our 608-RS lists 608-2RS among its interchange numbers.
Can I use a 608-2RS instead of a 608ZZ?
Yes, it fits the same shaft and housing. A contact seal gives more drag and a lower limiting speed (one maker lists 23,000 rpm against 34,000 rpm with grease) in exchange for better dust and water proofing.
How much does a 608ZZ bearing weigh?
About 12 g. Makers' reference figures for a shielded 608 are 12 g and 0.0122 kg.
What are the best 608 bearings?
There's no single best. Boundary dimensions follow ISO standards, which is why every maker's 608 we checked is 8 x 22 x 7. Choose shields or seals for the job, then the maker you prefer.
Related reading
- Bearing seal codes: 2RS vs ZZ, and each maker's equivalent
- Bearing size chart 6000 to 6310, plus 608
- How to replace the bearings in your skateboard or roller skates (our video)
Sources
- NTN, Ball and Roller Bearings, Cat. No. 2203/E: Miniature and Small Size Ball Bearings, p. B-45 and dimension table pp. B-50 to B-51 (ntnglobal.com/en/products/catalog/pdf/2203E_b03.pdf), read 2 October 2026.
- NTN, Ball and Roller Bearings, Cat. No. 2203/E: Deep Groove Ball Bearings, Table 1 p. B-17 and the d 22 mm table (ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf), read 2 October 2026.
- NTN, Ball and Roller Bearings, Cat. No. 2203/E: Bearing Tolerances, Table 6.2 p. A-54 (ntnglobal.com/en/products/catalog/pdf/2203E_a06.pdf), read 2 October 2026.
- Koyo (JTEKT), product details 608, 608 ZZ and 608 2RS (koyo.jtekt.co.jp/en/products/detail/?pno=608), read 2 October 2026.
- NSK, product pages 608, 608ZZ1, 608VV and 608DD Series, extra small and miniature ball bearings, metric series (nsk.com/engineering/products/bearings/ball-bearings/deep-groove-ball-bearings/extra-small-ball-bearings-and-miniature-ball-bearings-metric-series/608-esm-md.html, and the 608zz1, 608vv and 608dd pages beside it), read 2 October 2026.
Checked against NTN's catalogue, Koyo's and NSK's product pages and our product listings on 2 October 2026.
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