... A,B,X42,X46,X52,X56,X60,X65,X70,X High Quality Carbon Steel Drill Pipe We can produced drilling pipe( ... walking beam quenching furnace,, hot and cold straighten device, friction welding machine, middle frequency heat treatment, numerical control lathe and compete ... end, magnetic particle inspection, friction welding, seam inspection. We strictly carry out API spec Q1 quality control system and API Spec ...