Henan Shenlong Petroleum Drilling Tools Co., Ltd, a U.S.-China joint enterprise, is one of world leading manufacturers of the high quality petroleum drilling tools based in mainland China. We are dedicated to servicing the oil and gas exploration and oil drilling industries on a global basis. Our main products are slick drill collar, spiral drill collar, heavy weight drill pipe, stabilizer and Kelly. ShenlongÃ?¢??s products have been proved by many oilfields: there is no thread gluing and no fracture after they drill 600 hours. Our products can last much longer time than any other competitors&＃039;. We assure every piece of product leaving our facility conforms to the requirements of API SPEC 7-1. Drill collars we provide are from 4 3/4" to 11", Heavy weight drill pipes are from 3 1/2" to 5 1/2" We provide free thread protector for both box and pin. We are confident to provide you with high quality casting on basis of competitive price, And you will be assured that your every enquiry will receive our prompt and careful attention.