... 3. Used in coal gasect and nautral air conveyance. We are a manufacturer of malleable iron pipe fittings, mainly produce class 150 ... nipples, unions, plug, bends, caps, bushing, cross, cross over, backnut and flange ... Thread standard: NPT,BS,DIN Edge: banded, beaded, plain ... .4 MpaTensile strength HB180>330N/mmElongation > 8%Hardnessand nut balck malleable iron pipe fitting, gas thing