BEARING TOLERANCES

METRIC BEARINGS

The Tolerance Tables found on pages 381 through 386 covering bearings stocked by Consolidated conform to the Anti-Friction Bearing Manufacturers Association (AFBMA) and the International Standards Organization (ISO) standards. However, tolerance standards have not been established for Needle Roller Bearings, Self-Aligning Ball Bushings and Linear Recirculating Ball Bearings by either AFBMA or ISO.

These bearings are available in Tolerance Classes, STANDARD (ABEC-1) (no markings), P/6 (ABEC-3), P/5 (ABEC-5) and P/4 (ABEC-7). Bearings in Tolerance Classes P/5 (ABEC-5) and P/4 (ABEC-7) are ideal for special applications such as machine tool spindles.

INCH BEARINGS

Our inch series of bearings are only available in STANDARD Tolerance Class (no markings), which conform to British Standards for external dimension limits and running accuracy.

To clarify the headings and symbols used in these Tolerance Tables, the following definitions will apply.

d = Nominal bearing bore diameter

d min = The minimum diameter reading obtained by two-point measurements of a bearing bore having out-of-roundness and taper

d max = The maximum diameter reading obtained by two-point measurements of a bearing bore having out-of-roundness and taper

dm = (d max + d min / 2) for a particular bearing

D = Nominal bearing outside diameter

D min = The minimum diameter reading obtained by two-point measurements of a bearing outside surface having out-of-roundness and taper

D max = The maximum diameter reading obtained by two-point measurements of a bearing outside surface having out-of-roundness and taper

Dm = (D max + D min / 2) for a particular bearing

= A bearing ring width is the distance between the points of intersection between the two sides of the ring and a straight line perpendicular to one of the sides.

B = Width of bearing

T = Overall bearing width of Tapered Roller Bearings

Radial Runout =

Inner Ring: The radial runout of a radial bearing is the difference between the maximum and minimum indicator readings taken on the bore while rotating the inner ring one revolution.

Outer Ring: The radial runout of a radial bearing outer ring is the difference between the minimum and maximum reading when rotating the outer ring one revolution with arbor stationary.

Axial Runout = Thrust Bearings - Maximum variation of shaft or housing washer thickness.

H = Bearing height - Thrust Bearings.