Indexable Milling Inserts Milling Insert Chip Breakers Chip Breaker Application Large positive rake angle with sharp cutting edge for AL Non-ferrous materials. for Aluminum Large positive rake angle with sharp cutting edge for FG finishing cutting in steel. Finishing SM Sharp geometry design for Semi-finishing cutting in steel, SG stainless and difficult-to-cut material. Semi-Finishing MF MM Low cutting force for medium cutting in steel, stainless and MG cast iron. Medium RG Strong geometry design for rough cutting in steel, alloy steel and hardened steel. Roughing HG Strong, negative and big chamfering cutting edge for roughing, forging and cast skin. Heavy-Roughing A277