1.Ensure materials are authentic 2.Strict production process and testing process 3. long lasting,fasting drilling

meterial:  M35 CO

thermal treatment:  bit part 63-67HRC

                                    bit shank 40-50HRC

surface treatmen:  polished

 (The surface of the drill bit without tipping blunt crack significant bump and grinding burn and influence the use performance defect,Product no surface rupture, burr, rust, black spots or other undesirable phenomenon)

shank:  three flats shank,

flute type: straight flute

min-max	steps	description	overl length	shank	max thickness
4-32mm	15	4-6-8-10-12-14-16-18-20-22-24-26-28-30-32mm	101mm	7mm	5mm

,

straight flute step drill