Irwin 10234 Step Drill Bit, 3 16" to 7 8", Black Oxide HSS, 3 Flats Shank G509691386 Standards Meets C1 Food Service Standards Meets C1 Food Service Applications System of Measurement Inch Housing Material Aluminum Alloy Bearing Material Aluminum Alloy Bearing Insert Type Spherical Roller Dynamic Load Rating 12 The IRWIN UNIBIT 4 Step Drill Bit is a high speed steel tool with a black oxide finish 7 8 in Maximum Hole Size 7 8 in Minimum Hole Size 3 16 in Maximum Drilling Depth 1 8 in Number Hole Sizes 12 Shank Type Machining Straight with Three Flats Material Machining High Speed Steel Finish Machining Black Oxide Number of Flutes 1 Number of Pieces 1 Impact Rated Not Impact Rated Decimal Equivalent 0