Mortiser - Other Methods of Cutting Mortises

Other Methods of Cutting Mortises

Traditionally, a mortise would be cut by hand, using a chisel and mallet. However, due to the precision of fit required for a mortise and tenon joint, this can be a difficult and time-consuming task.

Other tools such as a router could be used for the task, but the router usually requires special attachments, jigs or templates and the router bit leaves rounded corners that might need to be squared by hand with a chisel. Alternatively, the tenon can be rounded with a rasp to achieve an equally strong joint.

For cutting small mortises, a normal drill bit can be used. However, for larger mortises, a common type of bit in modern mortisers is a Harry Watt square drill bit, in which a bit with a Reuleaux triangle cross section is allowed to "wobble" while it rotates within a square with rounded corners (compare to the motion of a Wankel engine). This type of bit removes all but the corners of the material to be removed, leaving very little to be cut by the chisel.