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?
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).
Those drill square holes; it’s a drill bit and a chisel combined, basically
OHHHHHHHHHH. That’s cool!