Steel structure design common norms are as followsStandardISO9001:2000CertificateAWS Welder Passport From USA"Steel Design Code" (GB50017-2003)"Cold-formed steel structure technical specifications" (GB50018-2002)"Construction Quality Acceptance of Steel" (GB50205-2001)"Technical Specification for welded steel structure" (JGJ81-2002,Website:://.cnhousesteel.com, J218-2002)"Technical Specification for Steel Structures of Tall Buildings" (JGJ99-9)Commonly used steel grades and performance of steelCarbon structural steelQ195, Q215, Q235, Q255, Q275, etc.Type of steelHigh-strength low-alloy structural steelQuality carbon structural steel and alloy structural steelSpecial purpose steel