Spiral drill. Blade angle 118°, helix angle 25 - 35°, tolerance Ø h 8, high-speed steel with increased cutting efficiency; for drilling alloyed and unalloyed steel and cast steel up to approx. helix inclination 25 - 35°, tolerance Ø h 8, high-speed steel with increased cutting efficiency; for drilling alloyed and unalloyed steel and cast steel up to approx.