Hollow Chisel Mortiser
This is as single purpose as a tool gets. It does one thing and one thing very well. It cuts square holes.
It cuts square holes!
If you need to cut square or rectangle mortises you could use one of these. In my shoji screen projects and door project this tool saved me lots of time.
When cutting through mortises or stop mortises by hand it is really easy to ruin that piece of wood. a slip of the hand chisel can mar the surface and change the look of the finished product.
The mortiser comes with four different chisels. Four very sharp chisels. Watch your fingers. The drill eats the stock away and the chisel squares the hole.