• High hardness, unique stepped structure, a drill can open a variety of size aperture.
                             

                             
• Suitable for these work-pieces that hardness is lower than 25 degree and the thickness is beyond 4mm, such as aluminum parts, insulation board, PVC plate, etc.
                             

                             
• The central punch is not needed, small shaking, hard to be broken.
                             

                             
• Used with pistol drill or bench drill, water it to cool while working to prolong its life, the proper drilling speed is 250-400 rpm.
                             

                         

                                                                                                                                 

                             

                             
• Material: HSS 4241
                             

                             
• Shank: hex shank
                             

                             
• Shank diameter: 6mm
                             

                             
• Groove: spiral 
                             

                             
• Surface treatment: Nitriding black
                             

                             
•        Step quantities           Step diameter                                                Net weight
                             

                         

                                                   

 

                                                   

001    5 steps                 4,  6， 8， 10， 12mm                           approx. 20g

                                                           

 

                                                           

 

                                                           

002    9 steps                 4, 6, 8, 10, 12, 14, 16, 18, 20mm                                    approx. 42g

                                                                   

 

                                                                   

 

                                                                           003    15 steps               4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32mm      approx. 137g                                                                          

 

                                                                                                                                                                       

                                             

                                             
• 1x HSS Hex Shank Nitriding Black Spiral Groove Step Drill Bit