Sprocket Catalog

SPROCKETS 101

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.

Maximum Bore Diameter: Refers to the maximum bore size diameter a sprocket can be machined to without compromising structural integrity. This term is associated with both “B” and “C” style sprockets. Please refer to Figure 4 for illustration. Length Thru Bore: “LTB” Refers to the inside hub diameter and the length to which it was machined. This machined length must be long enough to accommodate the proper size keyway to withstand shear and torque stress induced by the rotating shaft. Please refer to Figure 4 for illustration. Plain Bore: Associated with “A,” “B” and “C” style sprockets where there is no special machining performed to accommodate keyways or set screws, only a hole to accommodate shaft diameter. Please refer to Figure 6 for illustrations of Plain Bore sprockets. Finished Bore: Associated with “B” and “C” style sprockets where the inside diameter of the hub is machined with a standard keyway and two set screws. Finished bore hubs can also be machined to specific requirements depending on the needs of the application. Please refer to Figure 5 for an illustration. Sprocket Hub Style: U.S. Tsubaki manu- facturers various sprocket hub styles to meet the application requirements of our customers. Please refer to Figure 6 for the various stock style hub configurations offered by U.S. Tsubaki.

Basic Terminology ANSI Chain Pitch:

CALIPER DIAMETER

Figure 3 - Measuring sprocket outside diameter

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. 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. Sprocket Outside Diameter: Sprocket outside diameter is the measure- ment 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 illus- tration as to how this dimension is measured.

TOOTH (NOMINAL)

Figure 1 - Chain pitch measurement points (P)

LTB

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"

STYLES TYPEB

STYLEE TYPEB

Figure 4 - Maximum bore diameter and thru bore

Table 1 - ANSI Standard Chain Pitch Table

Figure 5 - Finished bore sprocket

TOOTH (NOMINAL)

Y LTB

LTB

TOOTH (NOMINAL)

LTB

TOOTH (NOMINAL)

STYLEE TYPEB X

STYLES TYPEB X

TYPEA

STYLES TYPEB LTB

STYLEE TYPEB LTB

LTB STYLEE TYPEB

LTB STYLED TYPEC

LTB STYLES TYPEB

STYLEE TYPEC

Figure 2 - Measuring caliper diameter

Figure 6 - Stock sprocket hub styles

TOOTH (NOMINAL)