Irwin 88885 5 Pc. Speedbor Spade Bit Drill Set Blue Groove Double cutting spurs scribe the outside of the hole reducing breakout 10% larger shank for added durability Grooved hex shank prevents slipping in drill chuck or bit extension Fits all standard quick change chucks Shorter bit length gets into confined spaces (between studs) where standard lengths will not fit. Includes: 3/8, 1/2, 5/8, 3/4, 1"