General Purpose Rougher - Series 100 Series 100 General Purpose Roughing End Mill. View Speeds and Feeds page. Features: Recommened for general purpose applications in material upto 50Rc Suggested for use in normalized carbon and alloy steels, cast steels, stainless steels, cast irons, brass and bronze. 30 Degree Helix 4 Flute (1" End Mills have 5 Flutes) Course Pitch Geometry Corner Radius standard to strengthen end teeth Available in nACRo® (Part number ends in 5), AlTiN (Part Number ends in 4) and TiCN (Part Number ends in 2) coatings