The common material is 20# and Q345. Technical standard: API 5L B, ASTM A106 GR. B, ASTM A53 GR. B. Our seamless steel pipes include: High-pressure boiler pipe GB5310-1995, special pipe for fertilizer making GB6479-2000, pipe for petroleum craking GB9948-2000, Low-and-medium-pressure boiler pipe GB3087-1999, fluid pipe GB/T8163-1999, structural pipe GB/T8162-1999 and hydraulic support pipe GB/T17396-1998. We can produce all kinds of seamless steel pipes according to your requirement and standard. please contact me at stjesse9(at)gmail(dot)com