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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 6723-2008 Cold forming sectional steel - Open sectional steel for general structure - Dimensions, shape, weight and permissible tolerances and the following main changes have been made with respect to GB/T 6723-2008:
——The standard name is modified;
——The “order contents” is added;
——The product specification is added;
——The equilateral flanging angle steel is added;
——The technical requirements are added.
This standard was proposed by the China Iron and Steel Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous editions of this standard are as follows:
——GB/T 6723-1986, GB/T 6723-2002 and GB/T 6723-2008.
Cold forming open section steel for general structure
1 Scope
This standard specifies the order contents, classification, code, sectional dimension and permissible deviations, length and permissible deviation, profile, technical requirements, weight and marking example for cold forming open section steel for general structure.
This standard is applicable to cold forming open section steel for general structure (hereinafter referred to as section steel) which is produced from cold-rolled or hot-rolled steel strip on the consecutive roller cold forming units.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6725 General requirements of cold forming steel sections
3 Order contents
Contracts or orders made based on this standard shall cover the following items:
a) Standard No.;
b) Product name;
c) Grade;
d) Delivery weight;
e) Dimension and profile;
f) Special requirements.
4 Classification and code
The section steel is classified into 9 classes coded respectively as follows:
5.1 The section shapes and marking symbols for section steel
The section shapes and marking symbols for section steel are shown in Figures 1~9. As agreed upon between the supplier and the purchaser and indicated in the contract, section steel other than those with section shape given in Figures 1~9 may be supplied.
5.2 Dimension, theoretical weight, sectional area and main parameters of section steel
The dimensions, theoretical weight, sectional area and main parameters of section steel are shown in Tables 1~9. As agreed upon between the supplier and the purchaser and indicated in the contract, section steel other than those with dimension given in Table 1~9 may be supplied, with the parameters negotiated between the supplier and the purchaser.
Keys:
b——side width;
t——side thickness;
R——inner arc radius;
Figure 1 Cold-formed equal angle steel (JD)
Keys:
B——long side width;
b——short side width;
t——side thickness;
R——inner arc radius;
Figure 2 Cold-formed unequal angle steel (JB)
Keys:
B——side width;
H——height;
t——side thickness;
R——inner arc radius;
Figure 3 Cold-formed unequal angle steel (CD)
Foreword II 1 Scope 2 Normative references 3 Order contents 4 Classification and code 5 Sectional dimension and permissible deviation 6 Length and permissible deviation 7 Profile 8 Technical requirements 9 Weight 10 Marking example
说明： b——边宽度； t——边厚度； a——卷边高度； R——弧半径。 图9卷边等边角钢(JJ) 表1 冷弯等边角钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心Y0 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 b×b×t b t Ix=Iy Iu Iv rx=ry ru rv Wy max=Wx max Wy min=Wx min
表2冷弯不等边角钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 B×b×t B b t Y0 X0 Ix Iy Iu Iv rx ry ru rv Wx max Wx min Wy max Wy min
表3冷弯等边槽钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心X0 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 H×B×t H B t Ix Iy rx ry Wx Wy max Wy min
表4冷弯不等边槽钢基本尺寸与主要参数 规格 尺寸 mm 理论 重量 kg/m 截面 面积 cm2 重心 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 H×B×b×t H B b t X0 Y0 Ix Iy Iu Iv rx ry ru rv Wx max Wx min Wy max Wy min
表5冷弯内卷边槽钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 H×B×C×t H B C t X0 Ix Iy rx ry Wx Wy max Wy min
表6冷弯外卷边槽钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 H×B×C×t H B C t X0 Ix Iy rx ry Wx Wy max Wy min
表7冷弯Z形钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 惯性矩 cm4 回转半径 cm 惯性积矩 cm4 截面模数 cm3 角度 H×B×t H B t Ix Iy Iu Iv rv Ixy Wx Wy tanα
表8 冷弯卷边Z形钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 惯性矩 cm4 回转半径 cm 惯性积矩 cm4 截面模数 cm3 角度 H×B×C×t H B C t Ix Iy Iu Iv rv Ixy Wx Wy tanα
表9卷边等边角钢基本尺寸与主要参数 规格 尺寸 mm 理论重量 kg/m 截面面积 cm2 重心Y0 cm 惯性矩 cm4 回转半径 cm 截面模数 cm3 b×a×t b a t Ix=Iy Iu Iv rx=ry ru rv Wy max=Wx max Wy min=Wx min
