They do indeed really cut square holes. They’re called mortising bits. Like the other commentor stated, they’re basically a combination of a chisel and a drill. The drill does most of the work in waste removal while the square blades give you 90° corners.
One could also potentially consider a rotary broach to be a “square drill” (supposing that it is a square and not a hex or other shape).
Are those really square or do they just stop drift?
Those drill square holes; it’s a drill bit and a chisel combined, basically
OHHHHHHHHHH. That’s cool!
They do indeed really cut square holes. They’re called mortising bits. Like the other commentor stated, they’re basically a combination of a chisel and a drill. The drill does most of the work in waste removal while the square blades give you 90° corners.
One could also potentially consider a rotary broach to be a “square drill” (supposing that it is a square and not a hex or other shape).