Own facility:API, ISO standerd (alloy steel E.X.G.S) OD :2 3/8,2 7/8,3 1/2,4,4 1/2,5(inch) UPSET: IU,EU, IEU We are factory specializing in the manufacture and export of drill pipe, drill collars and drilling joints (API and other standerds) for more than six years. We have profuse designs with series quality grade, and expressly, our price is very competitive because we are manufactory, we are ...