HSS spiral grooved step drills 6-38mm

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

1.    meterial:  M35 CO

2.    thermal treatment:  bit part 63-67HRC

                                    bit shank 40-50HRC

3.    surface treatmen:  ti coated

       (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)

4.   shank:  three flats shank  (CNC milling machine control, handle uniformity division.)

5.   groove type: spiral grooved  (Spiral groove step drills cutting speed is faster and less wear on the bit, chip removal more powerful and durable, the noise is smaller, spiral groove step drills use of better)

min-max	steps	description	overl length	shank	max thickness
6-38mm	15	6-9-13-16-19-21-23-26-22-24-26-29-32-35-38mm	100.5mm	7mm	5mm

HSS spiral grooved step drills 6-38mm