1 PrefaceModifythisstandardbyEN10219.1 2006"finegraincarbonsteelandcoldformedwelded steel structural hollowsections of Part 1: Technical delivery conditions",the maindifferences are as follows:--- Of steel grades and grades according to the corresponding standards and grades;--- Sampling,testing methods,re-inspection ofthe relevantrules, according tonationalstandards.This standard replaces GB/T6725-2002 "cold-formed steel."The revision of the standard content of the following techniques were modified:--- Adjusted normative references;--- Increase product yield strength classification;--- Increase the fine-grained steel;--- Increase the mechanical properties of the product specific assessment targets.Appendix A of this standard for the informative appendix.The standard proposed by the China Iron and Steel Association.This standard is standardized by the National Steel Technical Committee.Thedraftingofthis standard:ShanghaiBaosteelConstructionDesignandResearchInstitute,WuhanIron andSteelGroup HankouRollingMill, SteelPlantCo.,Ltd.,Guangzhou,FoshanCity,ChiofSteelPipeManufacturing Co.,Ltd.,ShanghaiJiayiCold-Formed Steel.Main drafters of this standard: Yu MATRIX, Qian, the Mayue Feng, Xiu-Fang Zhang, Li Ye,Zhang Yongqi, Li Jianzhang, Zhang Jing.Thisstandard replacesthe previouslyissued standardis:---GB/T6725-1986,GB/T6725-1992, GB/T6725-2002.1. ScopeThis standard specifies thecontent of cold-formed steel ordering, classificationand codename, size, shape,weight and tolerance, technical requirements,test methods,inspectionrules, packaging,marking andqualitycertification. Thisstandardapplies tocoldrolled orhot rolleddeformedsteel sheetand stripina continuousroller bendingmachine on the production of cold-formed steel.2. Reference StandardThe terms ofthe following documents by thestandard reference in the provisionsof thisstandard.Fordatedreferences, subsequentamendments(excludingcorrections)orrevisionsdonot applytothisstandard,however, encouragethepartiestoreachanagreement based on this standard to study whether the latest version of these documents .For undated references, the latest version applies to this standard.Chemical composition of steel products GB/T222 ToleranceGB/T228 roomtemperature tensiletest methodsfor metallicmaterials (GB/T228-2002,eqvISO6892: 1998 (E))GB/T229 metal materials Charpypendulum impact test method (GB/T229-2007,2 免费下载 ISO148-1: 2006, MOD)GB/T232 metal bending test method (GB/T232-1999, eqvISO7438: 1985 (E))GB/T699 q