American standard chains are covered by ISO 606, ANSI B29.1 and DIN 8188 and eight versions are covered.
- SIMPLEX, DUPLEX and TRIPLEX as for the European standard chains.
- QUADRUPLEX, 4 strands.
- QUINTUPLEX, 5 strands.
- SEXTUPLEX, 6 strands.
- OCTUPLEX, 8 strands.
- DECUPLEX, 10 strands.
The pitch sizes covered by this standard are 1/4 to 3 inch pitch. American standard chains have a smaller pin diameter than their European standard equivalent. Wear resistance is therefore reduced when compared with European standard chains with the one exception, 5/8 inch pitch. In this case the pin and bush diameter is larger in an American standard chain.
American standard chains are normally referred to under the ANSI standard numbering system, for example a 1/2 inch pitch duplex chain would be, ANSI 40-2.
The ANSI numbering system works as follows:
- The first number is the pitch size in 1/8 inch, ie 4/8 = 1/2 inch pitch.
- The second number refers to the chain being a roller chain, 0 = roller chain. A 5 replacing the 0 would indicate a bush chain.
- The suffix, as with European standard chain, refers to the number of strands in the chain, that is 2 = duplex chain.
ANSI chain is also available in heavy duty options with thicker plates (H) and through hardened pins (V). An ANSI heavy chain would be specified using these suffixes. ie. ANSI 140-2HV Duplex, thick plates, through hardened pin ANSI 80H Simplex, thick plates
Chains manufactured to the above standards are covered by ISO606 and DIN 8187. These standards cover 3 versions:
The range of pitch sizes can vary between 4mm, (0.158 inch) to 114.3mm, (4.500 inch). They are characterised by a large pin diameter, especially for the larger pitch sizes. This results in better wear resistance due to the greater bearing area.
The ISO standard has a simple form of part numbering, for example:
- 1/2 inch pitch duplex chain would be 08B-2.
- The first two digits are the pitch size in 1/16s of an inch, therefore 08 = 8/16 or 1/2 inch.
- The letter "B" indicates European Standard.
- The suffix 2 indicates the number of strands in the chain, in this case a duplex chain.