A keyway broach is a tool that is used to create the keyway for a gear or for a timing pulley. This type of tool has a series of teeth that cut progressively deeper as the shaft is inserted into the item that needs to be broached. A collared or plain bushing is attached to keep the shank of the broach centered during the cutting process.
Without a keyway broach, a lathe and a square cutting blank might be used to achieve a similar result, but for the best in accuracy the proper tool is needed. The keyway broach will ensure that your cut is exactly as desired.
You can purchase a keyway broach from a number of places. In the US, duMont is one company that produces them. There are also several Asian companies from which you can purchase an imported option. Both metric and Imperial keyway broaches can be purchased, although surprisingly it is the American company, duMont, that offers a metric version.
duMont also sells a keyway broach set featuring their “Minute Man” line of broaches. These sets come in a wooden box and feature a combination of several broaches to meet various needs. The company offers keyway broach sets with differing levels of size so that you can locate the right set for all of your projects. The sets come in regular, heavy duty, and metric, so you can take your pick.
Before you purchase a keyway broach or set, be sure of your measurements so that you get the right size. It’s a good idea to speak with an expert on the usage of the broach before you get started on your cutting. This will make certain that you have exactly the tool you need and can use it precisely as intended for the best possible results.