Master Mechanic, 6 Piece, Spade Bit Set, Contains 3/8", 1/2" 5/8", 3/4", 7//8" & 1" Diameter By 6" Standard Length Wood Boring Bits, Quick Change Hex Shank, Micro-Groove Point & Cutting Edges With Extended Spurs For Faster, Cleaner Boring Action, Heat Treated For Extra Strength.