NANJING ZHONGKUAN METAL MATERIAL CO., LTD. is a professional machining and trade of seamless steel pipes. Our company are agent of the iron and steel group.we supply the Fluid class pipe, structure pipe, high middle low pressure boiler tube and power plant , petrochemical, and oil and gas various materials alloy pipe , GB/T97113.3-2005 enforce the highest standards and the domestic standare API American Petroleum Association. 1. Seamless steel pipe(standard GB/8163-1999 materials 20# 20G) Pipe diameter Thickness 168.3 5.6 7.1 11 14.2 219.1 6.3 8 12.5 17.5 273 7.1 8.8 12.5 16 17.5 22.5 25 323.9 8.8 10 12.5 14.2 17.5 22.2 25 28 355.6 10 11 12.5 16 20 25 28 32 406.4 10 12.5 17.5 22.5 28 30 36 457 10 12.5 14.2 17.5 20 25 30 36 40 508 10 12.5 16 20 28 32 40 45 50 559 10 12.5 25 28 36 40 50 55 610 10 12.5 14.2 17.5 32 40 45 55 60 2. Longitudinal steel pipes (standard GB/T9711.3-2005 API materials :20# 16MN Q235B) Pipe diameter Thickness(mm) 400 10-30 500 10-35 600 10-35 700 10-40 800 10-40 900 10-45 1000 10-45 At the same time , my company also provide spiral steel pipe , stainless steel pipe , Alloy steel pipes . We can supply best price and good quality !welcome to cooperation with my company ! NANKING ZHONGKUAN METAL MATERIAL CO., LTD WEB:http://xxxxx FAX: 86-025-57066566 Phone: 86-025-57046566 MSN:xxxxx E-mail:xxxxx Contact person :Allen