1 China seamless steel pipes 2 OD21.3-813mm, Thk,1.24-59.54mm, ... 4 Cert ISO API More information about our products.1 China seamless steel pipes2 OD21.3-813mm, Thk,1.24-59.54mm ... . Looking forwards to your special inquiries,my friends.CHENGDU DERBO STEEL CO.,LTDAdd:Room No.B1025 Meinian Plaza Tianfu Avenue Chengdu ...