For many years, roller chain manufacturers furnished for specific installations an economical power transmission chain differing only in pitch from the standardized series of transmission roller chains which conformed to American Standard ASA B29.1.
Such practice became so common and the chains of such universal use that in 1948 the Roller Chain Technical Committee of the Association of Roller Chain Manufacturers, now known as the American Chain Association, developed these standards which were submitted for adoption as an American Standard.
This Standard describes a limited series of double-pitch power transmission roller chains which supplements the base chain series conforming to the standard B29.1. These chains differ from the base chains only in pitch, which is double that of the corresponding base chain. Supplementary information in Appendix A on speed and power transmission ratings indicates their special usefulness for drives operating at slow to moderate speeds, with moderate loads and long center distances.
In tabulating dimensional information in this Standard, customary inch-pound units have been used. Additionally, companion tabulations have been included in order to provide translations of these values into metric (SI) units in accordance with ASME Guide SI-1, ASME Orientation and Guide for Use of SI (Metric) Units. For this reason, certain formulas and relationships have been intentionally presented only in customary units so as to preclude any ambiguity between them and the tabulated values.
This revision of ASME B29.3M-1994 incorporates a restatement of the definition of Minimum Ultimate Tensile Strength and minor changes in the values for maximum pin diameter and minimum bushing inner diameter. The dimensional changes are to allow a direct error-free conversion from customary inch units to metric (SI) units. Similar changes are being made in the International Standard ISO 1275.
ASME B29.3M-1994 was approved by the American National Standards Institute on March 15, 1994.