Keyway Milling Cutters

Mark the slot width, length, depth and end shape, with the datum used to measure depth. A depth measured from the shaft surface and a dimension measured across the remaining shaft are not the same drawing instruction.

Identify whether the keyway opens at the shaft end or has closed ends. Show adjacent shoulders and the available approach direction. These details affect cutter access and the usable cutting length; they cannot be recovered from a photograph of the shaft diameter alone.

For a closed slot, the entry method must suit the selected tool. Do not assume every keyway cutter can plunge straight into solid material: center-cutting capability, ramping limits or a prepared entry hole need to be established for the proposed cutter and process.

Specify the finished slot tolerance and end radius, then identify the proposed cutter diameter, cutting length, overall length and shank or taper. The cutter and machining strategy must be considered together; selecting a nominal diameter alone is not a guarantee of the finished key fit.

If an arbor-mounted cutter is being considered for a side-accessible groove, compare the side-and-face milling cutter range and check body and arbor clearance. It is not an automatic substitute for a shank-type keyway cutter.

Useful inquiry attachments are the dimensioned slot drawing, workpiece material and hardness, machine connection, holder projection and the existing cutter marking. For entry-method terminology, see ISCAR’s explanation of center-cutting slot drills; it does not establish the capability of an unconfirmed FuRui model.