... 1.Basic component materials: HSS, cobalt high speed steel, carbide, M2, M35, M42 and G15 2.Straight or spiral flute Basic component ... materials: HSS, cobalt high speed steel, carbide, M2, M35 ... blind holeVarious helix angle can deal with different materials, scheduling the pieces HSS piral Fluted Tap or Sprial Pointed Tap for Deep Hole