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

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

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