W casings are made in DCDMA standards ,the most popular sizesand are AW, BW, NW, NWA, HW, and PW standards applied in geotechnial drilling. Raw materials: We choose the best steel tubes in the market to manufacture our rods and pipes. Instant check will be conducted after the raw material is delivered to our plant so that it canmake sure the compositions and specifications meet the inspection form the suppliers. Heat treatment control: Heat treatment will greatly make sure the material strength and the thread wear life of the rods and casings. We conduct either tru-wall or both ends heat treatment to the tube body. Thread opening process: Precision of threads will impact the use effects and serve time of drill rod and casings. CNC latches and form cutter are used in thread opening process to minimize error . Additional thread treatment: Surface of the threads will be cleaned to remove burr adhered after threads are opened. At last , the tread surface will be phosphated to improve surface conditions. Casing and the core tube specification
