Illustration of Keyway BROACHING

A method for machining internal keyways

In the case of external keyways,  milling is the most commonly used and efficient machining proces .

For internal keyways, however, milling cannot be used, but instead, a more time-consuming process is used where, in a multi-operation machine, a cutter repeatedly shaves material away layer by layer until the keyway has reached its final shape.

If the keyway to be cut is continuous, PULL BROACHING is often used as a SEQUENTIAL operation to free up machine time.

Pull broaching
A cutting tool is pulled axially through a hole to gradually transform it into the desired shape and tolerance
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