It is known as the chain saw mortiser. In indoor woodwork especially, an immense quantity of mortise and tenon work has to be done, and machines for the purpose have been used for many years.

Although they had a chainsaw, trying to cut a mortise with it by hand turned out to be super dangerous because the chainsaw would kick up every time the tip of the blade touched the wood.

Although they had a chainsaw, trying to cut a mortise with it by hand turned out to be super dangerous because the chainsaw would kick up every time the tip of the blade touched the wood.