What are the dimensions of a 608 bearing?

How it is worked out

1. Type6 → deep-groove ball bearing
2. Series0 → series 60 · extra-light · dimension series 10
3. Bore code8 → 8 mm (miniature: the last digit is the bore)

d = bore code × 5 mm (04+) · 00 = 10 · 01 = 12 · 02 = 15 · 03 = 17 mm

Worth knowing

In inches

0.315 × 0.866 × 0.276 in. A metric bearing: inch-series bearings (R8, 1600…) do not fit the same shaft.

2RS · 2RS1 · 2RSH · DDU · LLU

Rubber seal on both sides, greased for life. Best against dirt and water, slightly more drag. The same bearing by brand: SKF 608-2RSH or -2RS1, FAG 608-2RSR, NSK 608DDU, NTN 608LLU.

ZZ · 2Z · 2ZR

Metal shield on both sides. Less friction and more speed than a seal, but not watertight. SKF 608-2Z, FAG 608-2ZR, NSK and NTN 608ZZ.

RS · Z

Seal (RS) or shield (Z) on one side only, the other side open: for bearings fed oil or grease by the machine.

C3

Internal clearance larger than normal. Standard on electric motors and wherever the shaft runs hot or the fit is tight. Replace a C3 with a C3.

Interchangeable?

Yes. ISO 15 fixes the bore, outside diameter and width, so a 608 from any maker fits the same shaft and housing. Seals, cage, clearance and quality are what differ.

Skateboards

The 608 is the skateboard, scooter and fidget-spinner bearing: 8 mm axle, 22 mm wheel seat.

Other bores in the 60 series

Same 8 mm bore, other series

Do it with your own numbers

Got a number off a bearing with suffixes on it? Paste it into the bearing number decoder: it reads the whole designation, seals and clearance included.

Keep it on the wall

This answer is one row of the printable bearing size chart — one A4 or Letter page, free, no sign-up.