Step Drill Bit, High Speed Steel, TiN, 1/8 in to 1/2 in Size Range, Hex/ SHANK WIDTH ACROSS WRENCH FLATS: 0.250 INCHES NOMINAL CUTTING DIAMETER RANGE: 0.125 TO 0.500 INCHES FLUTE QUANTITY: 1 STEP QUANTITY: 13 DRIVE SHANK TYPE: MALE STRAIGHT HEXAGON FEATURES PROVIDED: SELF-STARTING MATERIAL: SURFACE TREATMENT: