Drills have one or more teeth and are rotary cutters used to remove a thin layer of metal from the machined surface of a hole. The hole after the reamer can get the exact size and shape. The non-standard drill reamer is used to ream the drilled hole on the workpiece, which can improve the machining accuracy of the hole and reduce the roughness of its surface. It is a tool used for finishing or semi-finishing of holes. Machining allowances are generally small.

The drill bit is divided into five parts: water hole, bearing, slap, roller cone and drill bit body. These five parts are currently common on the market: extended drill, step drill, non-standard drill bit, high-speed steel internal cooling drill, internal cooling drill, high-speed steel parabolic deep hole Different types of drills, taper shank twist drills, etc.

The factors that affect the drilling speed are:
1. The higher the formation hardness, the slower the drill bit runs;

2. Wellbore stability;

3. The size of the formation dip;

4. Whether the formation pressure system is complex or not;

5. Large size wellbore length.

When drilling steel, ensure adequate cooling and use a metal cutting fluid. Through good drill pipe rigidity and guide rail clearance, the drilling accuracy and drill life can be improved. To ensure the flatness and cleanliness between the magnetic base and the workpiece. When drilling thin plates, the workpiece should be reinforced; when drilling large workpieces, the stability of the workpiece should be ensured. At the beginning and end of drilling, reduce the feed by 1/3. The iron chips wrapped around the drill body should be removed in time to ensure smooth chip removal.

Ningbo Tiangong Great Star Tools Co.,Ltd since 1971,enjoys great prestige in the professional manufacture masonry drill company of the circle and now is the important production foundation for hand tools.Ningbo Tiangong Great Star Tools Co.,Ltd has developed from needle file and hundred RMB net capital into a corporation with 280 employees and more than 0.1 billion RMB net assets.Ningbo Tiangong Great Star Tools Co.,Ltd since 1958. The registering capital is about 4.15 million RMB. The company covers 30 thousand square meters, building area covers 23 thousand square meters. Company has more than 280 employees and sales amount was 20 million USD in last year. Its main products include hand tools, wood chisel, wood plane, flat wood bit,cold chisel,SDS&masonry drill bit, file&rasp etc. Company passed ISO9001 and BSCI quality management system, and GS, TUV, FSC product quality certification. Ningbo Tiangong Great Star Tools Co.,Ltd is also the permanent members in Ningbo National Hardware Association.Company main products include: wood chisel, wood plane, flat wood bit,cold chisel,drill bit, file&rasp etc.