BEARINGDEX
Angular contact ball

7308 bearing

40 mm bore, 90 mm outside diameter, 23 mm width (1.5748 × 3.5433 × 0.9055 in).

Dimensions

mminch
Bore d401.5748
Outside diameter D903.5433
Width B230.9055

Quick numbers

Pitch diameter dm65.0 mm
Section height (D − d)/225.0 mm
n·dm at 1,800 rpm117,000
n·dm at 3,600 rpm234,000

Compare against the maker's limiting speed. Speed calculator · L10 life

What the number means

7Angular contact ball
3Diameter series 3: medium. Width series 0 is implied and left off.
08Bore code 08 × 5 = 40 mm

Same size, different bearing

These share the 40 × 90 × 23 mm envelope but carry load differently. They aren't drop-in swaps.