TABLE 5. MINIATURE STANDARD ABEC/ISO TOLERANCES - OUTER RING
Outer Ring Bearing O.D. O.D. Size +0.0000 in. , +0.000 mm.
Dmp, Dm (1)
Width Variation V
Cs
Raceway Radial Runout K
e
Miniature and Instrument P Tolerances Over Including 3P 5P 7P 9P 3P 5P 7P 9P 3P 5P 7P 9P in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm 0.0000 0.70866 -0.0003 -0.0002 -0.0002 -0.0001 0.0051 0.0025 0.0013 0.0102 0.0051 0.0038 0.0013 0.000 18.000 -0.0076 -0.0051 -0.0051 -0.0025 N/A 0.0002 0.0001 0.00005 0.0004 0.0002 0.00015 0.00005 0.70867 1.1250 -0.0003 -0.0002 -0.0002 -0.00015 0.0051 0.0025 0.0013 0.0102 0.0051 0.0038 0.0025 18.000 28.575 -0.0076 -0.0051 -0.0051 -0.0038 N/A 0.0002 0.0001 0.00005 0.0004 0.0002 0.00015 0.0001
NOTE: Applies to all miniature and instrument bearings as well as 610 and 812 thin-section bearings. NOTE: P tolerances per ABMA std. 12.2.
(1) Dm
O.D. tolerance applicable to ABEC 3P only, all other O.D. size tolerances to
Dmp
definition per ABMA std 12.2.
TOLERANCES
ENGINEERING 20 TIMKEN MINIATURE AND THIN-SECTION BEARINGS CATALOG
TOLERANCES
Timken miniature, instrument and thin-section bearings are manufactured in accordance with tolerance classes specified by American National Standards Institute (ANSI) and the American Bearing Manufacturer's Association (ABMA). ANSI/ ABMA Standard 12 covers miniature and instrument bearings and Standard 26 covers thin-section bearings. Timken miniature, instrument and thin-section bearings are manufactured in precision classes from ABEC 3 (lowest) to ABEC 9 (highest) with the most common being ABEC 5 or 7. Please note the ANSI/ABMA does not define an ABEC 9 class for thin-section bearings. For applications that require a special tolerance not covered by any of these precision classes, please contact your Timken engineer. The tables that follow compare the tolerance features of the various ABEC classes for miniature, instrument and thin-section bearings. These tolerances relate to external dimensions as well as the geometric relationship of the ball groove with bearing mounting surfaces. These individual tolerance values provide a guide to the bearing user in designing his shaft and housings, since surfaces to which bearings are mounted should have tolerance levels equivalent to those on the corresponding bearing surface. Please note that the 610 and 812 bearings have tolerances controlled by the miniature and instrument bearing specification (Standard 12), even though they are dimensionally classified as thin-section parts.
TABLE 4. MINIATURE STANDARD ABEC/ISO TOLERANCES - INNER RING
Inner Ring Bearing Bore Bore Diameter +0.0000 in. , +0.000 mm.
dmp, dm (1)
Width Variation V
Bs
Raceway Radial Runout K
i
Miniature and Instrument P Tolerances Over Including 3P 5P 7P 9P 3P 5P 7P 9P 3P 5P 7P 9P in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm in. mm 0.0000 0.3937 -0.0002 -0.0002 -0.0002 -0.0002 0.0002 0.0001 0.00005 0.0002 0.00015 0.0001 0.00005 0.000 10.000 -0.0051 -0.0051 -0.0051 -0.0051 N/A 0.0051 0.0025 0.0013 0.0051 0.0038 0.0025 0.0013 0.3937 0.5000 -0.0002 -0.0002 -0.0002 -0.0002 0.0002 0.0001 0.00005 0.0003 0.00015 0.0001 0.00005 10.000 12.700 -0.0051 -0.0051 -0.0051 -0.0051 N/A 0.0051 0.0025 0.0013 0.0076 0.0038 0.0025 0.0013
NOTE: Applies to all miniature and instrument bearings as well as 610 and 812 thin-section bearings. NOTE: P tolerances per ABMA std. 12.2.
(1) dm
bore tolerance applicable to ABEC 3P only, all other bore size tolerances to
dmp
definition per ABMA std 12.2.
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