These High Speed Steel (HSS) Number Sizes Series J100 of jobber drills are general purpose drills for steels, cast steel, grey cast iron, malleable cast iron, nickel brass, aluminium alloy and graphite. Available in ana array of number sizes, the drills have a black oxide finish, a point angle of 118, a normal helix angle, a standard web thickness, a relief angle of 8 - 20, a tolerance of diameter of h8 and a tolerance of shank of f11. Features and Benefits Available in an array of number sizes to suit your needs Manufactured from High Speed Steel (HSS) for optimum resilience Black oxide finish bolsters durability Industrial quality for versatility of use Typical Applications Suited for drilling steels, cast steel, grey cast iron, malleable cast iron, nickel brass, aluminium alloy and graphite Standards ANSI B328 BS 328 DIN 338 Notes Gauge inch mm 80 0.014 0.343 79 0.015 0.368 78 0.016 0.406 77 0.018 0.457 76 0.020 0.508 75 0.021 0.533 74 0.023 0.572 73 0.02