Sprocket Catalog

ALTERATIONS BASIC TERMINOLOGY

The term “alteration” applies to a modification/change in configuration from standard for a stock sprocket. All U.S. Tsubaki sprockets can be “Altered” to meet select application requirements. The following provides a list of common alterations performed by U.S. Tsubaki to stock sprockets, and an explanation of what each is. In the event that the modification requested is not listed, it does not mean that the sprocket cannot be altered. However, it may mean that the alteration in question would require the sprocket be Made-To-Order (MTO) to meet the application requirements at hand. Please consult a U.S. Tsubaki Customer Service Representative to review additional options available for altered and MTO sprockets.

SPROCKET REBORING

Reboring is a process of changing the dimension or configuration of the sprocket inner hub diameter to meet the application requirements at hand. Typical reboring alterations include:

• Hub inside diameter dimension not listed as standard • Hub inside diameter dimension greater than standard • Hub inside diameter dimension smaller than standard • Metric inside hub diameter dimension • Hexagon broached inside diameter hub configuration • Splined broached inside diameter hub configuration • Change to Length Through Bore (LTB) dimension

LTB Figure 1 - Typical finished bore sprocket

Please reference Figure 1 for an illustration of a typical finished bore sprocket.

SPROCKET KEYWAY & SET SCREW

U.S. Tsubaki standard keyway configuration facilitates use of industry standard square key stock in inch sizes with use of common set screws. The standard keyway location is center line of tooth +/- 0.015”. Two set screws are furnished with finished bore sprockets. One set screw is placed directly over the keyway. The second set screw is

placed at 90 degrees from the keyway set screw Application requirements may demand a different keyway and set screw configuration than standard. Common alterations to standard keyway / set screw configurations include:

• Keyway non center line of tooth • Tapered keyway • Multiple keyways • Metric keyway • Metric set screws • Set screw location other than standard Please see Figure 2 for standard keyway locations.

Figure 2 Standard Keyway and set screw location

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