| Step drill bits Size: 6-60mm (12 steps: 6,10,15,20,25,30,35,40,45,50,55,60mm). Shank diameter: 13mm. Step drill Material: HSS 4241 Application: The step suitable for workpieces with hardness less than 25, such as carbon steel, sheet metal, insulation board , PVC panels, planks and wood. The workpiece thickness under 5mm. Note: Use water cooling in drilling to extend the life of the drill bit. Recommended drill speed 250-400 RPM. Spiral Groove Slot: 135 Split point tip and double flute design for self-centering and deburring, spiral groove helps eliminate chips during the piercing. | |