1. Unique stepped structure, one drill bit can open a variety of sizes and apertures, and one stepped drill hits a box of bits

2. No need to use center punch, which is not easy to break compared with ordinary twist drills. On site construction, a ladder drill is suitable for multiple specifications.

3. It becomes possible to remove burrs, chamfers, expand elliptical holes, and twist drills.

4. Compared with ordinary twist drills. It can open beautiful apertures without shaking, without leading the center punch.

5. Use tools: pistol drill and bench drill. Water cooling while working, can effectively extend the life of the drill bit, the recommended drilling speed is 250-400 rpm.

Material: High-speed steel 4241/6542 (suitable for workpieces with normal hardness, such as iron plate, plate thickness is about 1MM)

Specification: 4-32mm (4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32mm)

4-20mm (4, 6, 8, 10, 12, 14, 16, 18, 20mm)

4-12mm (4, 6, 8, 10, 12mm)