duMONT Minute Man® designs and manufactures custom application bushings to guide and support the broach as it passes through the workpiece enabling the operator to use individual Keyway Broaches in a variety of bore sizes. Custom bushings, plain or collared are available in both American standard and metric sizes. Each bushing is designed to accommodate the bore size you need, has the proper slot size for the broach you are using and can be manufactured in long lengths to work with broaches specifically designed for long lengths of cut. duMONT Minute Man® keyway broaches and bushings have letter designations signifying the width of the keyway broach and the guide slot in the Bushing. Oversized keyway broaches larger than 1″ or 25mm require the keyway size being used since they do not have a letter designation. The bushing size and Style are determined by the bore diameter of the workpiece as well as the length of cut and the Style of Broach to be used. “A” Style Broaches are used with “A” Style Bushings, “B-1” Style Broaches with “B-1” Style Bushings, etc. The Maximum Length of Cut with Push-Type Keyway Broaches should not exceed the length of the Bushing being used. Special Bushing designs are also available that allow for indexing of multiple keyways, and can accommodate multiple Broach Styles. Please contact factory for details.