The online power tool trade counter:
Chain mortisers, also known as spelt mortisers, are specialist carpentry tools that are used in timber framing, boat building and general carpentry. Chain mortisers are used to make square holes in pieces of wood, so that two pieces of wood can be joined. They operate in a similar fashion to a chainsaw, but the blade is kept straight and the end of the blade is plunged into the wood. Chain mortisers are typically able to plunge deep into wood, and cut relatively quickly.