ANSI B29.1, ISO R606, DIN 8188
ANSI standard chain is dimensionally similar to BS chain but with generally thicker plates resulting in a narrower b1 dimension between inner plates. The pitching between strands of duplex and triplex chain, dimension Pt may also vary from BS chain.
Care should be taken to ensure that correct sprockets are used with ANSI chain.

"H" SERIES ROLLER CHAINS
ANSI “H” Series chains are dimensionally identical to ANSI standard chains except that the sideplates are thicker. The heavier side plates provide some additional fatigue resistance. They are primarily intended for applications where occasional shock loads are likely to cause fatigue failures in the chain. Whilst there is an increase in tensile strength, the wear life of the case hardened pins remains the same as for standard chain.
Simplex “H” series chains operate on standard ANSI sprockets. Multiple strand “H” chain require non-standard ANSI sprockets because of the thicker side plates.
