Amana Tool 51612 Metric SC Spiral for Steel, Stainless Steel & Non Ferrous Metal with AlTiN Coating 3-Flute x 4 D x 10 CH x 4 SHK x 48mm Long Up-Cut Router Bit/End Mill AlTiN coating has many benefits: Extra wear resistance Allows for faster feed and speed rates Cutting edge protected from wear Better chip evacuation Less heat build up Superior cutting quality and extended tool life SPECIFICATIONS: (D) Diameter: 4mm (B) Cutting Height: 10mm (d) Shank: 4mm Overall Length (L): 48mm Max RPM: 28,000 Flutes: 3