Chain Dimensions
Chain types are identified by number; ie. a number 40 chain. The rightmost digit is 0 for chain of the standard dimensions; 1 for lightweight chain; and 5 for rollerless bushing chain. The digits to the left indicate the pitch of the chain in eighths of an inch. For example, a number 40 chain would have a pitch of four-eighths of an inch, or 1/2", and would be of the standard dimensions in width, roller diameter, etc.
The roller diameter is "nearest binary fraction" (32nd of an inch) to 5/8ths of the pitch; pin diameter is half of roller diameter. The width of the chain, for "standard" (0 series) chain, is the nearest binary fraction to 5/8ths of the pitch; for narrow chains (1 series) width is 41% of the pitch. Sprocket thickness is approximately 85-90% of the roller width.
Plate thickness is 1/8th of the pitch, except "extra-heavy" chain, which is designated by the suffix H, and is 1/32" thicker
.
ANSI Standard Chain Dimensions
Chain No. Pitch Roller Dia. Roller Width Sprocket thickness Work Load
25 1/4" 0.130" 1/8" 0.110" 140 lbs
35 3/8" 0.200" 3/16" 0.168" 480 lbs
40 1/2" 5/16" 5/16" 0.284" 810 lbs
41 1/2" 0.306" 1/4" 0.227" 500 lbs
50 5/8" 0.400" 3/8" 0.343" 1400 lbs
60 3/4" 15/32" 1/2" 0.459" 1950 lbs
80 1" 5/8" 5/8" 0.575" 3300 lbs
Bicycle and Motorcycle Chain Dimensions
Chain No. Pitch Roller Dia. Roller Width Sprocket thickness
Bicycle, with Derailleur 1/2" 5/16" 1/8" 0.110"
Bicycle, without Derailleur 1/2" 5/16" 3/32" 0.084"
420 1/2" 5/16" 1/4" 0.227"
425 1/2" 5/16" 5/16" 0.284"
428 1/2" 0.335" 5/16" 0.284"
520 5/8" 0.400" 1/4" 0.227"
525 5/8" 0.400" 5/16" 0.284"
530 5/8" 0.400" 3/8" 0.343"
630 3/4" 15/32" 3/8" 0.343"