3.00 mm Cutter Diameter x 4.50 mm Length of Cut Carbide Ball End Mill For Medium Alloy Steels, 3 Flutes, AlTiN Coated. Optimized for readily machinable medium alloy steels, stainless steels, and tool steels, this Harvey Tool fully stocked offering features a variable helix design, which works to reduce chatter and harmonics while increasing material removal rates (MRR).