The most widely used one in oil drilling and geological drilling is cone bit. Cone bit is of impact, crushing and shearing crushing rock role in rotation, so cone bit can adapt to various strata of soft, medium and hard. Especially after the appearance of jet type roller bit and rock bit cone bit nozzle, the drilling speed is greatly improved, which is a great revolution in the history of the development of cone bit. Cone bit by tooth type can be divided into milling (steel teeth) teeth roller bit. (rock inlaid on the hard alloy tooth roller cone bit; according to the cone number) can be divided into single, double cone roller, roller and a three roller bit. At present, at home and abroad, the most common and most used one is three cone bit.
In the oil drilling industry and all kinds of cone bits, it is an important and indispensable part of roller bit, but for some of drilling industry, the price is too high, which has led some drilling industry had a great interest in the secondary cone bit. Its price is low and quality is reliable (in petroleum drilling using only the life of 1/3) , reduces a lot of cost for drilling industry. So the second hand of cone bit has become an important part for some drilling industry.