Sell 3pc 4-12/20/32mm Step Drill Bits Spiral Grooved Center Drill Bit Solid Carbide Mini Drill Titanium Step Cone Metal Drill Bit best price

Step drill bit 4-12mm 4-20mm 4-32mm hexagon shank core step drill taper cutting tool, hexagon shank straight groove step drill, for woodworking wood metal Feature: 1. Unique stepped structure, a drill bit can open a variety of specifications and sizes of apertures, and a step drill can fit a box of drill bits. 2. No center punch is needed, and it is not easy to break compared with ordinary twist drills. For on-site construction, one step drill is suitable for multiple specifications. 3. It becomes possible to deburr, chamfer, open oval holes to expand, and functions that twist drills cannot accomplish. 4. Compared with ordinary twist drills. The shaking is small, and the beautiful aperture can be opened without using the center punch. 5. Use tools: pistol drill, bench drill. Water injection cooling while working can effectively extend the life of the drill bit. The recommended drilling speed is 250-400 rpm. 6. These step drill bits are very suitable for various materials from metal, plastic, fiberglass to wood. They also help to expand existing holes, and the two-slot design technique allows faster penetration without chipping. Caution: 1. It is only suitable for workpieces with a hardness of less than 25 degrees, such as carbon steel, plates, insulation boards, wood boards, etc. 2. The thickness must be less than 5mm. Specification: Material: high-speed steel 4241 (suitable for workpieces with general hardness) Handle: 1/4" hexagonal handle Color: golden Size 4-12mm: (4,6,8,10,12mm) 4-20mm: (4, 6, 8, 10, 12, 14, 16, 18, 20mm) 4-32mm: (4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32mm)