we can supply various of drill pipe , comply with api standard Heavy weight drill pipe The wall thickness of heavy weight drill pipe is between drill pipe and drill collar, its structure is similiar with drill pipe. Size 3-1/2, 4, 4-1/2, 5, 5-1/2, 6-5/8 RSC type NC38, NC40, NC46, NC50, 5-1/2FH, 6-5/8FH Material AISI 4145H