Variable tooth unique variable tooth geometry for consistent cutting ability in a wide range of materials Manufactured to strict Alpha specifications to suit demanding Australian conditions 8% cobalt Bi-metal gives ultimate performance and superior welding technology prevents tooth strippage 38mm cutting depth Recommended Speeds Mild Steel 390 Cast Iron 260 Tool Steel Stainless 195 Brass 520 Aluminium 585 Wood 3000 Recommended for use with a small arbor .