ASME/ANSI Standard Short-Pitch 32b Precision Alloy/Carbon Steel/Stainless Steel Martin General Hardware Roller Chains

For mnemonic purposes, below is another presentation of key dimensions from the same standard, expressed in fractions of an inch (which was part of the thinking behind the choice of preferred numbers in the ANSI standard):

Notes:
1. The pitch is the distance between roller centers. The width is the distance between the link plates (i.e. slightly more than the roller width to allow for clearance).
2. The right-hand digit of the standard denotes 0 = normal chain, 1 = lightweight chain, 5 = rollerless bushing chain.
3. The left-hand digit denotes the number of eighths of an inch that make up the pitch.
4. An "H" following the standard number denotes heavyweight chain. A hyphenated number following the standard number denotes double-strand (2), triple-strand (3), and so on. Thus 60H-3 denotes number 60 heavyweight triple-strand chain.
 A typical bicycle chain (for derailleur gears) uses narrow 1⁄2-inch-pitch chain. The width of the chain is variable, and does not affect the load capacity. The more sprockets at the rear wheel (historically 3-6, nowadays 7-12 sprockets), the narrower the chain. Chains are sold according to the number of speeds they are designed to work with, for example, "10 speed chain". Hub gear or single speed bicycles use 1/2" x 1/8" chains, where 1/8" refers to the maximum thickness of a sprocket that can be used with the chain.

Typically chains with parallel shaped links have an even number of links, with each narrow link followed by a broad one. Chains built up with a uniform type of link, narrow at one and broad at the other end, can be made with an odd number of links, which can be an advantage to adapt to a special chainwheel-distance; on the other side such a chain tends to be not so strong.

Roller chains made using ISO standard are sometimes called as isochains.