Machinery's Handbook, 31st Edition
Ball and Roller Bearings 2461 Table 13. AFBMA and American National Standard Tolerance Limits for Needle Roller Bearing Inner Rings—Inch Type NIR ANSI/ABMA 18.2-1982 (R1999)
Basic Bore Diameter d
Allowable Deviation from d of Single Mean Diameter, d mp
Allowable Deviation From F of Single Mean Diameter, F mp
Basic Outside Diameter, F
Allowable Deviation from Width, B
Inch
Inch
Inch
Inch
Inch
Over
Incl.
High
Low Over
Incl.
High
Low High
Low
0.3937 0.7087 0.7087 1.0236 1.0236 1.1811 1.1811 1.3780 1.3780 1.9685 1.9685 3.1496 3.1496 3.9370 3.9370 4.7244 4.7244 5.5118 5.5118 7.0866 7.0866 8.2677 8.2677 9.2520
+0 +0 +0 +0 +0 +0 +0
− 0.0005 − 0.0007 − 0.0009 − 0.0009 − 0.0010 − 0.0011 − 0.0013 − 0.0015 − 0.0015 − 0.0017 − 0.0019 − 0.0020
− 0.0009 0.3125 0.7500 − 0.0012 0.7500 2.0000 − 0.0014 2.0000 3.2500 − 0.0015 3.2500 4.2500 − 0.0016 4.2500 4.7500 − 0.0018 4.7500 7.0000 − 0.0022 7.0000 8.0000
− 0.0004 +0.0100 +0.0050 − 0.0005 +0.0100 +0.0050 − 0.0006 +0.0100 +0.0050 − 0.0008 +0.0100 +0.0050 − 0.0008 +0.0150 +0.0100 − 0.0010 +0.0150 +0.0100 − 0.0012 +0.0150 +0.0100
− 0.0024… … … … … … − 0.0025… … … … … … − 0.0027… … … … … … − 0.0031… … … … … … − 0.0032… … … … … …
For fitting and mounting practice, see Table 21. Metric Radial Ball and Roller Bearing Shaft and Housing Fits.— To select the proper fits, it is necessary to consider the type and extent of the load, bearing type, and certain other design and performance requirements. The required shaft and housing fits are indicated in Table 14 and Table 15. The terms “Light,” “Normal,” and “Heavy” loads refer to radial loads that are generally within the following limits, with some overlap ( C being the Basic Load Rating computed in accor- dance with AFBMA-ANSI Standards):
Radial Load
Bearing Type
Light
Normal
Heavy
Ball
Up to 0.075 C Up to 0.075 C Up to 0.075 C
From 0.075 C to 0.15 C From 0.075 C to 0.2 C From 0.070 C to 0.25 C
Over 0.15 C Over 0.15 C
Cylindrical Roller Spherical Roller
Over 0.15 C Shaft Fits: Table 14 indicates the initial approach to shaft fit selection. Note that for most normal applications where the shaft rotates and the radial load direction is constant, an interference fit should be used. Also, the heavier the load, the greater is the required inter ference. For stationary shaft conditions and constant radial load direction, the inner ring may be moderately loose on the shaft. For pure thrust (axial) loading, heavy interference fits are not necessary; only a moder ately loose to tight fit is needed. The upper part of Table 16 shows how the shaft diameters for various ANSI shaft limit classifications deviate from the basic bore diameters. Table 17 gives metric values for the shaft diameter and housing bore tolerance limits given in Table 16. The lower parts of Table 16 and Table 17 show how housing bores for various ANSI hole limit classifications deviate from the basic shaft outside diameters.
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