Roller chains are available in various designs:
DIN 8187 (European standard)
DIN 8188 (American standard)
Long-linked chains
Company standard chains
Examples of the different types of chains:
Simplex chain, also known as a single-strand chain. This is the most common form of roller chain.
Duplex chain, also known as a double-strand chain.
Triplex chain
The term "long-linked chains" refers to chains that in terms of their internal workings are similar to a standard Simplex chain, but which have a double pitch. They are frequently used in the construction of agricultural machinery.