Feature: 1. With seamless steel pipe design, has a longer life, can be well balanced in use, and is not easy to deform 2. The seamless steel pipe sintered with high‑quality diamond powder is more tough and durable 3. Simple to use and easy to replace, it can meet your needs and ensure your operating efficiency 4. Equipped with concentric shafts, drilling faster, and the drill bit does not deviate from the center during work 5. Compatible with a variety of equipment, suitable for hand‑held drilling rigs/bench‑type drilling rigs Specification: Item Type: Diamond Drill Bits Wall Thickness: Approx. 4mm/0.15in Drill Body: 45# Seamless Steel Pipe Knife Tooth: Flat Tooth Diameter: Approx. Φ18mm/0.70in, Φ20mm/0.78in, Φ22mm/0.86in, Φ25mm/0.98in, Φ27mm/1.06in, Φ30mm/1.18in Length: Approx. 370mm/14.6in Tooth Characteristics: Top Flat Tooth Early Use: Drilling and Sharpening Speed Later Period of Use: After Using for a Period of Time, the Speed Drops Scope of Application: Multi-story Residential Brick-concrete Structures, Engineering Subways, Bridges, Expressways. Package List: 1 x Diamond Drill Bits Note: When opening the hole, first incline 45° to open the small groove, then slowly straighten the drill bit, and make the hole vertically.It is strictly forbidden to use the electric hammer function, and it is recommended to use the electric drill functionPlease note that the the opening number of this product is randomly issued with double openings and triple openings.