Putnam Center Cutting Square End Mill, Fractional Size: 1/8 IN, Decimal Equivalent: 0.1250 IN, Overall Length: 3-1/16 IN, Cut Length: 3/8 IN, Shank Diameter: 3/8 IN, Straight With Weldon Flats Shank, Number Of Flutes: 4, List Style: 435, High Speed Steel, Bright Finish, Hand Of Spiral Cut: RHS/RHC, Metric Size: 3.18 MM, For Alloy Steel, Tool Steel, Carbon Steel, Cast Iron