Niagara Cutter N40400 High Speed Steel Square Nose End Mill, Weldon Shank, TiN Finish, Roughing and Finishing Cutting, 30-Degree, 4-Flute, 4.5" OAL, 1.250" Cut Diameter, 1.250" Shank Diameter Designed for turning operations  roughing to medium machining -- on aluminum in average machining conditions H13A uncoated carbide grade provides a balance of hardness and toughness for resistance to wear and shock Square shape offers edge strength and is suitable for roughing, facing, interrupted cuts, and large lead angles Roughing (KR) and medium-machining (KM) chipbreaker styles help prevent chip buildup at a range of cutting depths and feed rates Positive single-sided insert with 7-degree clearance angle for light cutting forces and side clearance