Drill collars we produce is made from 4145H forging or rolling ,modified steel. We manage our production and inspection process strictly according to API SPEC7 requirements. All connections are phosphate-coated to improve resistance to corrision. We also do copper plating according to clients's requirements. We offer slip groove elevator according to clients's requirements. We probide free thread protector for both pin and box.

Different sizes we produce is form 3 1/2" to 11", our strength is large size like above 9" and small size like below 4 3/4".