... ,S20CK ASTM,AISI,SAE:1020 BS:050A20,060A20 seamless steel pipe for low pressure boilerCarbon steel; Stainless steel;Alloy steel boiler tube;pressure tube; oil pipe;structual ... GB9948-8810-530*1.5-36Boiler pipes for refinery,heatexchangeing pipes,seamless steel pipes for pipelineHigh-pressureSeamless pipes for fertilizer making equipment20, 16Mn,Q345GB6479-200018 ...