The development of bolt drilling rigs has gone through more than 30 years, and now there are leg-type electric bolt rigs, rig-type bolt rigs, outriggers and DIN rail type hydraulic bolt rigs, outrigger type pneumatic bolt rigs, etc. Pneumatic bolt machine manufacturers step by step into the right track. Coal mine bolt rigs are mostly rotary type. To match the promotion of small-diameter resin bolts, the drill bit is 27-29mm. Rotary drill bit, its structure type is mostly two wings symmetrical, two wing asymmetry and two wings reinforcement type, can be used to drill different rock selection. The drill pipe is machined from B19 (majority) or B22 (few) hexagonal hollow steels. After many years of joint research, the bolt bit and drill rod can initially meet the requirements of bolt support under certain conditions. However, due to the development, research, and production of anchor hole drilling equipment, it is not compatible with the rapid development of bolting technology. The traditional pneumatic rock drill and coal-powered drill are widely used in construction of coal mine bolts. Special bolt hole drilling equipment, the use of foreign imports of equipment more, but due to high prices of imported equipment and spare parts supply is not timely, coal mine users want to use domestic bolt hole drilling equipment. Assistant Drilling Equipments,Auxiliary Drilling Equipment,Drilling Equipment For Water Well,Core Drilling Equipment JIANGSU XI TEC ENVIRONMENTAL&DRILLING EQUIPMENT COMPANY CO.LTD , https://www.xitecdrilling.com