Tool joints for drill pipe for oil or natural gas well is a welding neck joint with drill pipe.Own facility:API, ISO standerd (O 

Joints are made of quality alloy steel through special heat treatment. Have the features of strong strength, good toughness, and long usage life. Surface of screw is copper-plated or phosphated. Good adhension-prevention. Mechanical feature meets the requirements in SY/T5290 and in API Spec7.