Optimal surface speeds vary by material type to balance stock removal with heat management: Mild Steels & Aluminum: 4,000 to 8,000 SFPM (Surface Feet Per Minute) for fast, aggressive stock removal. Stainless Steels & Cast Irons: 3,000 to 6,000 SFPM to control frictional heat buildup and prevent work hardening. Exotic Alloys (such as Titanium) & Plastics/Polymers: Below 2,000 SFPM to prevent thermal damage, melting, or warping. Woods & Fibrous Materials: Generally run up to 6,000 SFPM depending on the density and desired finish quality.