Square hole drill bit. Yes, you can... - World of Engineering

Square Hole Drill Bit Adapter for Easy Installation and Disassembly - Mortising Attachment for Drill Press, Mortise Machine, Power Tool Accessory for Drill Machines

Square Hole Drill Bit Adapter, High Manganese Steel Mortising Attachment for Drill Press, Square Hole Drill Fixing Bracket, Precise Drill Press Wood Mortise Accessory for Drill Press Hand Drill

Pousbo® Woodworking Square Hole Drill Bits（50%OFF）

Remaindert - Square hole drill bit for woodworking ✨Made...

The geometry behind a square hole drilling machine