Peculiarities: 100% new and high quality Made from high quality HSS steel Ideal for use in cutting holes in a variety of materials including steel, brass, wood, plastic, etc. Titanium plating to reduce power and heat Heat treated and polished. Drill bits Perfectly round holes in steel, brass, plastic, wood, etc. 3-sided shin design to prevent slippage when in a chuck Twin flute design is faster, smoother and cleaner cuts each step clearly marked with depth diameter in steps Function: Deburring, chamfering, cutting or reaming holes Auxiliary tools: gun drill, hand drill, charging drill, bench. (Water cooling during operation, can effectively extend the life of the drill, especially in the case of continuous drilling) Rotational speed: 3-12 Speed: 260-400 4-12 Speed: 260-400 4-20 Speed: 180-240 Attention: Because the outer diameter of each step of the step drill gradually expands, the corresponding cutting resistance and linear speed will also gradually increase. Because the step drill is completely dependent on the slant edge, which is only 1mm long, if the feed rate is too fast when drilling, it will be easily annealed, caused by beveled abrasion. Please do not press too hard when drilling to avoid edge wear. Suitable material: workpieces with general hardness, such as wood, plastic, PVC plate, iron plate, plate thickness within 3mm. Please note that stainless steel and spring steel are not applicable. Not for hardening. (Water cooling during operation, can effectively extend the life of the drill, especially in the case of continuous drilling) Length: 3-12mm Length: Approx. 7.9cm 4-12mm Length: Approx. 7.3cm 4-20mm Length: Approx. 5.5cm Blades are supplied in the following sizes: 3-12mm (3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm) 10 steps 4-12mm: (4mm, 6mm, 8mm, 10mm, 12mm) 5 steps 4-20mm :( 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm) 9 steps Package includes: 1 drill 3-12mm 1 drill 4-12mm 1 drill 4-20mm ( By choice ) Notes: 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee that the model of the real product does not differ from the one shown in the photo. 2.Please allow slight dimension difference due to different manual measurement.