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