Keyway for square-ended key

Usually in the machine shop the assembler makes round both ends of the key. Round-ended keys don’t bind in keyways that are made with an end mill cutter, but rounding the ends usually takes time (cost). One solution is to use standard commercial round-ended keys of the correct size which cost higher than making them from a rectangular bar. Machining the round-end of the keyway with a disc milling cutter (see figure above) is a second solution. If a square-ended key is placed in such keyway it couldn’t bind. An end mill and a disc cutter are the only tools needed for this machining operation.