heavy caliber carbon steel welding pipe 1)OD: 1/4''-48'' 2)WT: SCH5-SCH160 ... GRB, A53 GRB, API 5L,GRB, heavy caliber carbon steel welding pipe Company NameShijiazhuang Beihai Pipe CO.,LTDBusiness TypeMANUFACTURE AND EXPORTERProductspiral ... ,R3Thread:Plain end,STC,BTC,LTC heavy caliber carbon steel welding pipe