Spade Bit

A spade bit is a flat, paddle-shaped drill bit with a sharp point and two flat cutting edges, designed for fast, rough boring in wood -- running conduit or plumbing through framing is its classic job. It cuts quickly and cheaply but leaves a rougher hole with more tearout than a Forstner bit or a brad point bit, both of which trade speed for a cleaner, flatter-bottomed, more precisely located hole.