Item Type: Step Drill Bit Product Material: High speed steel (contains cobalt) Drillable Diameter: Approx. 4mm / 0.16in 6mm / 0.24in 8mm / 0.31in 10mm / 0.39in 12mm / 0.47in 14mm / 0.55in 16mm / 0.63in 18mm / 0.71in 20mm / 0.79in 22mm / 0.87in 24mm / 0.94in 26mm / 1.02in 28mm / 1.1in 30mm / 1.18in 32mm / 1.26in Applicable Materials: Suitable for drilling and reaming operations of 304 stainless steel, carbon steel, iron plate, aluminum plate, copper plate, plastic plate, etc. Package List 1 x Step Drill Bit Keeping the drill bit clean will help increase the drilling speed. 1HIGH SPEED STEEL MATERIAL: Step drill bit is made of high speed steel material, possess longer service life 2CUTTING FASTER AND SMOOTHER: Adopt double cutting blade design, cutting faster and smoother, bring high working efficiency 3ADVANCED DOUBLE SPIRAL GROOVE DESIGN: The advanced double spiral groove design is better than the straight groove design, which prolongs the service life of the drill bit 4DRILLING AND REAMING: Suitable for drilling and reaming operations of 304 stainless steel, carbon steel, iron plate, aluminum plate, copper plate, plastic plate, etc. 5432MM DRILLING DIAMETER: Come with 15 steps sizes, drillable diameter from 432mm, one step drill bit meet all your requirements