Sprocket Catalog

SPROCKET ESSENTIALS BASIC TERMINOLOGY

The following defines terminology and provides guidance to help select the best sprocket for a given application. In the event that further assistance is required, please call U.S. Tsubaki customer service at (800) 323-7790.

ANSI Chain Pitch: The term “chain pitch” refers to the roller pin center to roller pin center dimension of a given chain. The pitch is always measured in 1/8" increments. Please see Figure 1 for an illustration of how to measure chain pitch. Please see Table 1 for referencing ANSI Standard chain pitch sizes.

Figure 1 - Chain pitch measurement points (P)

Caliper Diameter: The term “caliper diameter” refers to the dimension measured from sprocket tooth valley to sprocket tooth valley on the opposite side (180°) of the sprocket. This dimension is used to measure the diameter of the sprocket plate (not including sprocket teeth). On sprockets that have an odd number of teeth, the measurement would be taken from the valley of one tooth to the valley as close to 180° on the opposite side of the sprocket. Please reference Figure 2 for an illustration of how this dimension is measured.

ANSI Standard Chain Pitch Size Pitch # Pitch in IN Pitch # Pitch in IN 25 1/4" 100 1-1/4" 35 3/8" 120 1-1/2" 40 1/2" 140 1-3/4" 41 1/2" 160 2" 50 5/8" 180 2-1/4" 60 3/4" 200 2-1/2" 80 1" 240 3"

Table 1 - ANSI Standard Chain Pitch Table

Sprocket Outside Diameter: Sprocket outside diameter is the measurement from sprocket tooth peak to sprocket tooth peak on the opposite (180°) side of the sprocket. For sprockets with an odd number of teeth, the measurement would be taken from the peak of one sprocket tooth to the peak of a tooth as close to 180° degrees as possible. Please refer to Figure 3 for an illustration as to how this dimension is measured.

Figure 2 - Measuring caliper diameter