Rod material, select cross-sectional shape, geometry, gauge length is based on the hardness of the size of the rock drill impact energy, rock drill bit diameter, rock hole depth, the use of drills to solder tail caudal peduncle connectivity requirements, as well as rock drills feeding methods to select the drill rod. Normally meet requirements under the premise of heavy drilling hollow steel drill rods, should try to select a moderate section, lighter, shorter length, rigidity, long life drill rod. For hand-held drill, generally used in connection taper, a hexagonal cross-section of H22, H25 drill rod, shank size of 108mm x H22, made of 55SiMnMo, 95CrMo etc; for Drifting rock, generally used in H25, H28, H32, H35 threaded connections with hexagonal cross-section diameter, reducers and quick-change drill rod (drill rod rock drill rod, drill pipe, hydraulic drilling rig drill pipe, drill rod, heavy drill rod, hydraulic drill). For production drilling (underground, open-pit mining) hollow steel, generally used in D35, D38, D45, D51, D60, D65, D76, D87 circular cross-section, with the diameter of threaded connections, reducers and quick-change drill rod and drill pole. Specifications Length selection principle is: be determined in accordance with the requirements of drilling depth, generally within the range of 0.3 --- 7.3mm. After the material is selected, heat threaded drill rod and ensure that the key is to improve the life of the drill rod. A heat treatment process abroad most foreign 25CrNi3Mo steel threaded drill rod selection, the overall gas carburizing process. The process have a large investment in deep gas carburizing furnace, which the carburized layer thickness, the surface carbon concentration, temperature carburizing, carburizing time, carburizing furnace atmosphere, cooling, etc., can be controlled by the microcomputer, so hollow drill steel drill rod, can guarantee to get a good quality and performance. After the whole carburizing, two thread re IF quenching and tempering to obtain high wear resistance threaded parts. Rod hardness is achieved by controlled cooling after carburizing overall. There are also some foreign manufacturers to choose low carbon CrNiMo Department of steel, quenched and tempered thread after two high-frequency quenching. Rod hardness is controlled at the time of the hollow steel rolling production to get the hardened layer thickness of the threaded portion of the general control of induction hardening 2.5 mm or less. Features abroad heat treatment process is: carburizing and induction hardening drill rod threaded surfaces can make to obtain high hardness and wear resistance, but also to obtain a high surface compressive stress. Surface compressive stress and lath martensite and austenite film-like structure within the slats can improve the surface fatigue strength, fatigue fracture threshold, reducing the fatigue crack propagation rate, which is to improve the life of the very thread Rod favorable. Hollow drill steel drill rod, Shandong Peng Rui Drilling Ltd. (certified), hollow steel drill by Shandong Peng Rui Technology Limited. Drilling Ltd. Shandong Peng Rui (www.zbpengrui.com) Shandong Zibo, metal cutting class leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Shandong Peng Rui Drilling Ltd. led the staff warmly welcome all inquiries negotiations to create Shandong Peng Rui Drilling Ltd. a better future.