Threaded connection supporting solder products in terms of varieties, specifications or in the quality and quantity are far more significant than the other way solder connection, has become the dominant rock drilling tools using the connection means. Due to the hydraulic rock drill steel ladder threaded hollow hexagonal seventies, making use of solder connecting thread in varying range of applications, a diameter less than φ64mm products are basically using R thread or TR (taper connection is threaded connection, with easy disassembly and high strength) threaded hollow steel, greater than or equal φ64mm use T thread. In recent years, with the development of hydraulic drilling equipment, has introduced the ST (double-headed thread) thread, GT thread, EL68 thread, T60 thread. These threads have a smaller torque tightening and removal of larger bearing wear area, and thus meets the use of heavy hydraulic rock drill rock drilling tools in large size. Currently used on the market of solder brazing with the main thread R and T-series two. EL68 and ST series thread mainly for the international market. R thread series including R22, R25, R28, R32, R35, R38 thread. R thread is mainly used for brazing with a tunnel or tunnel Drifting. R38 thread used to drill the hole is not deep drilling, normally do not need to take a long drill rod drilling workplace. T thread series include T38, T45, T51, T60 three threads, mainly used in deep, larger size solder and solder used on hydraulic rock. A metric thread R3212 thread for domestic use, pitch 12mm. Domestic for underground mining. The mid-1960s, because of the lack of Cr, Ni resources, research new steel alloy guiding ideology is to develop SiMnMo series, developed 35SiMnMoV steel threaded Rod as our recommendation of steel, and has been extended so far. But as the threaded steel drill rod, if the use of heat treatment process carburizing + tempering, because the high carbon content of the steel, and Si, Mn elements compared with Cr, Ni elements, especially in the high-intensity Under the circumstances, its tough plasticity index is much lower than CrNiMo steel lines; as carburizing isothermal quenching, the loss of surface hardness and compressive stress, reduce fatigue strength and wear resistance threaded rod hollow Rock Drilling steel, drill rod life is also difficult to improve. So, from the 1960s to the mid-1980s, China's threaded drill rod (mainly length greater than 1 200 mm in size) can only be used in low-temperature heat treatment process quenching and tempering or austempering, which is the life of our country and abroad Threaded Rod Compared to the big gap between the main reason. 25CrNi3Mo conventional mechanical properties of steel and steel 35SiMnMoV Table 1. As can be seen from the data in Table 1, under air cooling conditions, the impact toughness higher than SiMnMoV CrNi3Mo based system, and the strength is high. In the quenched state, strength and toughness during tempering CrNi3Mo Department, SiMnMoV line when you want to achieve or improve the tempering temperature isothermal hardening. If both after carburizing process to deal with according to Table 1, the threaded portion of the high surface hardness CrNi3Mo lines, high compressive stress, not only wearable but also improve the life; and SiMnMo Department elevated temperature or isothermal quenching and tempering, has decreased carburized threaded surface hardness, wear resistance and compressive residual stress, thereby shortening the service life. Hydraulic Rod hollow steel, hollow steel, Shandong Drilling Co., Ltd. Peng Rui Peng Rui provided by Shandong Drilling Technology Limited. Drilling Ltd. Shandong Peng Rui (www.zbpengrui.com) strong, credible, Shandong Zibo metal cutting and other industries has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Drilling Ltd. Shandong Peng Rui and you hand into the brilliant, for a better future!