The most important dimensions to measure are the Pitch (P), Roller Diameter (d1) and Inner Width (b1). Below are roller chain size charts for ANSI roller chain in single, double and triple strand. It's recommend to use calipers to accurately measure the roller chain. There are many chains that have the same pitch, but have different roller diameters and widths.

Single Strand ANSI Roller Chain Chart

single strand roller chain diagram

Dimensions: Inches

Nitro Chain Number Pitch Roller Width Roller Diameter Overall Width Pin Diameter Plate Height Plate Thickness
- P b1 d1 L d2 h2 T
25-1* 1/4 1/8 0.130 0.311 0.091 0.228 0.030
35-1* 3/8 3/16 0.200 0.488 0.141 0.346 0.050
40-1 1/2 5/16 0.312 0.653 0.156 0.469 0.060
41-1 1/2 1/4 0.306 0.541 0.141 0.390 0.050
50-1 5/8 3/8 0.400 0.815 0.200 0.585 0.080
60-1 3/4 1/2 0.469 1.020 0.234 0.709 0.094
80-1 1 5/8 0.625 1.287 0.312 0.949 0.125
100-1 1-1/4 3/4 0.750 1.590 0.375 1.188 0.156
120-1 1-1/2 1 0.875 1.980 0.437 1.425 0.187
140-1 1-3/4 1 1.000 2.141 0.500 1.663 0.219
160-1 2 1-1/4 1.125 2.551 0.562 1.889 0.250
180-1 2-1/4 1-13/32 1.406 2.866 0.687 2.047 0.281
200-1 2-1/2 1-1/2 1.562 3.161 0.781 2.375 0.312
240-1 3 1-7/8 1.875 3.760 0.937 2.791 0.375

* Rollerless chain. d1 = Bushing diameter

Double Strand ANSI Roller Chain Chart

double roller chain diagram

Dimensions: Inches

Nitro Chain Number Pitch Roller Width Roller Diameter Overall Width Pin Diameter Plate Height Plate Thickness
- P b1 d1 L d2 h2 T
35-2* 3/8 3/16 0.200 0.885 0.141 0.346 0.050
40-2 1/2 5/16 0.312 1.220 0.156 0.469 0.060
50-2 5/8 3/8 0.400 1.531 0.200 0.585 0.080
60-2 3/4 1/2 0.469 1.921 0.234 0.709 0.094
80-2 1 5/8 0.625 2.468 0.312 0.949 0.125
100-2 1-1/4 3/4 0.750 3.007 0.375 1.188 0.156
120-2 1-1/2 1 0.875 3.772 0.437 1.425 0.187
140-2 1-3/4 1 1.000 4.067 0.500 1.663 0.219
160-2 2 1-1/4 1.125 4.854 0.562 1.889 0.250
180-2 2-1/4 1-13/32 1.406 5.457 0.687 2.047 0.281
200-2 2-1/2 1-1/2 1.562 5.980 0.781 2.375 0.312
240-2 3 1-7/8 1.875 7.220 0.937 2.791 0.375

* Rollerless chain. d1 = Bushing diameter

Triple Strand ANSI Roller Chain Chart

Dimensions: Inches

Nitro Chain Number Pitch Roller Width Roller Diameter Overall Width Pin Diameter Plate Height Plate Thickness
- P b1 d1 L d2 h2 T
25-3* 1/4 1/8 0.130 0.827 0.091 0.228 0.030
35-3* 3/8 3/16 0.200 1.287 0.141 0.346 0.050
40-3 1/2 5/16 0.312 1.787 0.156 0.469 0.060
50-3 5/8 3/8 0.400 2.244 0.200 0.585 0.080
60-3 3/4 1/2 0.469 2.815 0.234 0.709 0.094
80-3 1 5/8 0.625 3.610 0.312 0.949 0.125
100-3 1-1/4 3/4 0.750 4.417 0.375 1.188 0.156
120-3 1-1/2 1 0.875 5.567 0.437 1.425 0.187
140-3 1-3/4 1 1.000 5.992 0.500 1.663 0.219
160-3 2 1-1/4 1.125 7.157 0.562 1.889 0.250
180-3 2-1/4 1-13/32 1.406 8.047 0.687 2.047 0.281
200-3 2-1/2 1-1/2 1.562 8.800 0.781 2.375 0.312
240-3 3 1-7/8 1.875 10.681 0.937 2.791 0.375

* Rollerless chain. d1 = Bushing diameter