Description:Material: High Speed SteelTitanium coated to reduce friction and heat, and increase service lifeSurface treatment for spiral flutes step drill: nitrogen treatmentPin punch spring drill for drill positioning, spiral flutes step drill for reaming and expandingApplications: steel, stainless steel ,non-ferrous metals, plastics and plexiglasSpecification:Nitrogen treatment increased hardness and abrasion resistance of the spiral flutes step drillSize:Approx. 4-32mm/ 0.18-1.26 inch, Shank Diameter: 10mm/ 0.39 inch(4,6,8,10,12,14,16,18,20,22,24,26,28,30,32mm/ 0.18,0.24,0.31,0.39,0.47,0.55,0.63,0.71,0.79,0.87,0.94,0.10,1.10,1.18,1.26 inch)Approx. 4-20mm/ 0.18-0.79 inch, Shank Diameter: 8mm/ 0.31 inch(4,6,8,10,12,14,16,18,20mm/ 0.18,0.24,0.31,0.39,0.47,0.55,0.63,0.71,0.79 inch)Approx. 4-12mm/ 0.18-0.47 inch, Shank Diameter: 6mm/ 0.24 inch(4,6,8,10,12mm/ 0.18,0.24,0.31,0.39,0.47 inch)Package Includes:1 Piece of Pin Punch Spring Drill3 Pieces of Spiral Flutes Step Drill'