Editing Mortiser (section)

==Square chisel mortiser==
[[File:Exhibition Hall, Summerlee - geograph.org.uk - 1471775.jpg|thumb|upright|Lever mortising machine, now disused and placed as a monument]]
The '''square chisel mortiser''' (also called ''hollow chisel mortiser''), similar to a [[drill press]] in many respects, combines the cutting of a four-sided chisel with the action of a [[drill bit]] in the center. The bit clears out most of the material to be removed, and the chisel ensures the edges are straight and clean. This device was invented in 1874 by [[Robert Greenlee|Robert]] and [[Ralph Greenlee]] (founders of the [[Greenlee|Greenlee Company]]).

The first square chisel lever mortisers were purely manual and relied on the operator pulling down on a large lever to push the chisel through the timber. An improvement was to place a rotating cylindrical auger inside a hollow chisel. This helps to clear chips up the centre of the chisel. As electric power became easily available, the auger developed as a drill bit and became the main means of removing waste timber from the mortise. These mortisers now used much shorter hand levers, as the manual work was only in cleaning up the mortise to be square-cornered.

Square chisel mortising bits can also be fitted to normal drill presses using a mortising attachment.

The Greenlee Company still manufactures mortisers, as do a large number of other [[power tool]] [[Woodworking tools manufacturers|manufacturers]].  It is a common tool in the woodshop of professional [[woodworker]]s, but because of its specialized nature, many amateur woodworkers would not make enough use of it to justify the moderately high cost and space this tool takes up in the woodshop.  Some smaller and less expensive models, suitable for cutting only narrow mortises are available.