the variable diameter tool joint of drill pipe is also called drill pipe connector and Kelly Sub,Tool Joint Sub,Crossover Sub product.Generally, it is made of high-quality low-carbon alloy steel with high mechanical properties after high-pressure forming and vacuum quenching and tempering. It is mainly divided into anchor cable drill pipe connector, geological drill pipe connector, hand-held pneumatic drill pipe connector, various drill pipe reducer connector and core casing reducer connector.
