scope:

FOREWORD

The formulation of a recommended standard for silent chain and sprocket tooth under The formulation of a recommended standard for silent chain and sprocket tooth form under 3/8 inch pitch became a matter of consideration by a Subcommittee of the Silent Chain Technical Committee of the Association of Roller and Silent Chain Manufacturers, Silent Chain Section in 1945.

The considerations were:

a. Engineering Standards to afford interchangeabi I ity of chains and sprockets in pitches below 3/8 inch.

b. Recommended practice for power transmission ratings and maximum RPM of sprockets.

Recommendations proposed by the Technical Committee were accepted by the Association of Roller and Silent Chain Manufacturers on January 22, 1947.

There is but one small pitch silent chain( less than 3/8 inch pitch)currently produced, namely, 3/16 inch pitch. However, the need for 1/8 inch or 1/4 inch pitch may develop and the established proportions wi II insure their interchangeability.

The desirability of proportionately larger pins in the sma II pitch chains is generally recognized; consequently, the chain joint in general will be a single unit.

 The basic standardization for the small pitch chains follows the same sound basis established for chains of larger pitch; namely "Prime basis for standardization to be a standardized sprocket design......

A standardized chain will be one which fits a standard sprocket of any number of teeth with the proper amount of operating clearance......."

 This Standard was reaf/irmed by the American National Standards Institute on April 10, 1974.