Part number. The part number consists of the following:
prefix letter M; general specification number; number of this
specification sheet; dash number; and characters for retainer,
closures, radial internal clearance or contact angle, calibration,
performance test, lubricant, and lubricant amount.
Radial internal clearance
Specification sheet number
M81793/25-BA7N4N2F1 indicates - Bore 0.0469"; outside diameter
0.1562"; width 0.0625"; radius
0.003"; retainer, phenolic laminate;
closures , none; contact angle,
greater than 14° but less than 20°;
no calibration; performance test,
starting torque - Grade A;
lubricant, MIL-L-81322; lubricant
amount, manufacturer's standard.