American standard chains are covered by DIN 8188, ANSI B29.1 and ISO 606. There are 8 versions:

• Simplex

Often referred to as ANSI standard, pitch size varies between inch to 3 inches, with the chain links having a smaller pin diameter. They are less wear resistant than European Standard chains except for the 5/8 inch which is larger.

The ANSI standard has a simple numbering system:

• The first number is the pitch size in 1/8 inch, for example 4/8 =