... A,B,X42,X46,X52,X56,X60,X65,X70,X High Quality Carbon Steel Drill Pipe We can produced drilling pipe(API5D ... friction welding machine, middle frequency heat treatment, numerical control lathe and compete set of ultrasonic inspection and magnetic particle inspection. The whole ... , seam inspection. We strictly carry out API spec Q1 quality control system and API Spec 5DP production standard. We have a ...