GB/T 702-2026 Dimensions,shape,weight and tolerances of steel bars English, Anglais, Englisch, Inglés, えいご
1 Scope
This document specifies the classification, sectional shape, sectional dimensions, weight and tolerances , length and tolerances, and the shape of hot-rolled steel bars (round, square, flat, hexagonal, octagonal), forged steel bars (round, square, flat), and cold-drawn steel bars (round, square, hexagonal).
This document applies to hot-rolled round steel with a nominal diameter of 5.5 mm to 400 mm and hot-rolled square steel with a side length of 5.5 mm to 300 mm; general-purpose hot-rolled flat steel with a thickness of 3 mm to 60 mm and a width of 10 mm to 200 mm; hot-rolled flat steel for tools and dies with a thickness of 4 mm to 100 mm and a width of 10 mm to 310 mm (general-purpose hot-rolled flat steel and hot-rolled flat steel for tools and dies are hereinafter collectively referred to as hot-rolled flat steel); hot-rolled hexagonal steel with a distance across flats of 8 mm to 70 mm and hot-rolled octagonal steel with a distance across flats of 16 mm to 40 mm.
This document applies to forged round steel with a nominal diameter of 40 mm to 1300 mm, forged square steel with a side length of 40 mm to 1000 mm, and forged flat steel with a thickness of 20 mm to 800 mm and a width of 40 mm to 1500 mm.
This document applies to cold-drawn round steel, square steel and hexagonal steel with a nominal dimension of 3 mm to 80 mm.
For corrosion-resistant alloys and high-temperature alloy bars, this document may be used as reference.
2 Normative references
No normative references are listed in this document.
3 Terms and definitions
No terms and definitions are defined in this document.
4 Classification
Steel bars are classified into the following four categories by the surface condition in case of delivery:
a) Hot-rolled/hot-forged steel bars: commonly known as black bars, delivered with the original surface (or after pickling, sandblasting).
b) Ground round steel (including hot-rolled ground round steel and hot-forged ground round steel): round bars whose surface has been ground and are delivered with a metallic luster surface.
c) Machined steel bars: bars whose surface has been milled and are delivered with a metallic luster surface.
d) Cold-drawn steel bars: bars processed by cold drawing and delivered with a smooth surface and high dimensional accuracy.
5 Sectional shape
5.1 The sectional shapes of round steel and square steel are shown in Figure 1.
Key
d - Diameter of round steel;
a - Side length of square steel;
r - Radius of rounded corners.
Figure 1 Sectional views of round steel and square steel
5.2 See Figure 2 for the sectional shape of flat steel.
Key
b - Width of flat steel;
t - Thickness of flat steel;
r - Radius of rounded corners.
Figure 2 Sectional view of flat steel
5.3 For the sectional shape of hexagonal steel and octagonal steel, see Figure 3.
Key
S - Distance across flats;
r - Radius of rounded corners.
Figure 3 Sectional views of hexagonal steel and octagonal steel
6 Sectional dimensions, weight and tolerances
6.1 Dimensions and weight
6.1.1 Hot-rolled steel bars
6.1.1.1 The dimensions and theoretical weight of hot-rolled round steel and square steel shall comply with the provisions of Table A.1.
6.1.1.2 The dimensions and theoretical weight of general-purpose hot-rolled flat steel shall comply with the provisions of Table A.2.
6.1.1.3 The dimensions and theoretical weight of hot-rolled flat steel for tools and dies shall comply with the provisions of Table A.3.
6.1.1.4 The dimensions and theoretical weight of hot-rolled hexagonal steel and hot-rolled octagonal steel shall comply with the provisions of Table A.4.
6.1.1.5 Agreed by the supplier and the purchaser and indicated in the contract, hot-rolled steel bars of other dimensions not specified in Tables A.1 to A.4 may also be supplied.
6.1.1.6 Hot-rolled steel bars should be delivered by actual weight. Agreed by the supplier and the purchaser and indicated in the contract, they may also be delivered by theoretical weight.
6.1.2 Forged steel bars
6.1.2.1 The dimensions and theoretical weight of forged round steel and square steel shall comply with the provisions of Table A.1.
6.1.2.2 The dimensions and theoretical weight of forged flat steel shall comply with the provisions of Table A.5.
6.1.2.3 Agreed by the supplier and the purchaser and indicated in the contract, forged steel bars of other dimensions not specified in Tables A.1 and A.5 may also be supplied.
6.1.2.4 The theoretical weight of forged steel bars with nominal dimensions exceeding the range specified in Tables A.1 and A.5 shall be determined through negotiation between the supplier and the purchaser.
6.1.2.5 Forged steel bars should be delivered by actual weight. Agreed by the supplier and the purchaser and indicated in the contract, they may also be delivered by theoretical weight.
6.1.3 Cold-drawn steel bars
6.1.3.1 The dimensions and theoretical weight of cold-drawn round steel, square steel and hexagonal steel shall comply with the provisions of Table A.6.
6.1.3.2 Agreed by the supplier and the purchaser and indicated in the contract, cold-drawn steel bars of other dimensions not specified in Table A.6 may also be supplied.
6.2 Tolerance of dimensions
6.2.1 Hot-rolled steel bars
6.2.1.1 The tolerances of dimensions of hot-rolled round steel and square steel shall comply with the provisions of Table 1. The dimension tolerance group may comply with the corresponding product standard or be indicated in the order contract; if not indicated in the product standard or contract, the tolerance of Group 3 shall apply.
Table 1 Tolerances of dimensions of hot-rolled round steel and square steel
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Sectional shape
6 Sectional dimensions, weight and tolerances
7 Length and tolerances
8 Shape
Annex A (Normative) Dimensions and theoretical weight of steel bars
Standard
GB/T 702-2026 Dimensions,shape,weight and tolerances of steel bars (English Version)
Standard No.
GB/T 702-2026
Status
to be valid
Language
English
File Format
PDF
Word Count
11000 words
Price(USD)
300.0
Implemented on
2026-11-1
Delivery
via email in 1~2 business day
Detail of GB/T 702-2026
Standard No.
GB/T 702-2026
English Name
Dimensions,shape,weight and tolerances of steel bars
GB/T 702-2026 Dimensions,shape,weight and tolerances of steel bars English, Anglais, Englisch, Inglés, えいご
1 Scope
This document specifies the classification, sectional shape, sectional dimensions, weight and tolerances , length and tolerances, and the shape of hot-rolled steel bars (round, square, flat, hexagonal, octagonal), forged steel bars (round, square, flat), and cold-drawn steel bars (round, square, hexagonal).
This document applies to hot-rolled round steel with a nominal diameter of 5.5 mm to 400 mm and hot-rolled square steel with a side length of 5.5 mm to 300 mm; general-purpose hot-rolled flat steel with a thickness of 3 mm to 60 mm and a width of 10 mm to 200 mm; hot-rolled flat steel for tools and dies with a thickness of 4 mm to 100 mm and a width of 10 mm to 310 mm (general-purpose hot-rolled flat steel and hot-rolled flat steel for tools and dies are hereinafter collectively referred to as hot-rolled flat steel); hot-rolled hexagonal steel with a distance across flats of 8 mm to 70 mm and hot-rolled octagonal steel with a distance across flats of 16 mm to 40 mm.
This document applies to forged round steel with a nominal diameter of 40 mm to 1300 mm, forged square steel with a side length of 40 mm to 1000 mm, and forged flat steel with a thickness of 20 mm to 800 mm and a width of 40 mm to 1500 mm.
This document applies to cold-drawn round steel, square steel and hexagonal steel with a nominal dimension of 3 mm to 80 mm.
For corrosion-resistant alloys and high-temperature alloy bars, this document may be used as reference.
2 Normative references
No normative references are listed in this document.
3 Terms and definitions
No terms and definitions are defined in this document.
4 Classification
Steel bars are classified into the following four categories by the surface condition in case of delivery:
a) Hot-rolled/hot-forged steel bars: commonly known as black bars, delivered with the original surface (or after pickling, sandblasting).
b) Ground round steel (including hot-rolled ground round steel and hot-forged ground round steel): round bars whose surface has been ground and are delivered with a metallic luster surface.
c) Machined steel bars: bars whose surface has been milled and are delivered with a metallic luster surface.
d) Cold-drawn steel bars: bars processed by cold drawing and delivered with a smooth surface and high dimensional accuracy.
5 Sectional shape
5.1 The sectional shapes of round steel and square steel are shown in Figure 1.
Key
d - Diameter of round steel;
a - Side length of square steel;
r - Radius of rounded corners.
Figure 1 Sectional views of round steel and square steel
5.2 See Figure 2 for the sectional shape of flat steel.
Key
b - Width of flat steel;
t - Thickness of flat steel;
r - Radius of rounded corners.
Figure 2 Sectional view of flat steel
5.3 For the sectional shape of hexagonal steel and octagonal steel, see Figure 3.
Key
S - Distance across flats;
r - Radius of rounded corners.
Figure 3 Sectional views of hexagonal steel and octagonal steel
6 Sectional dimensions, weight and tolerances
6.1 Dimensions and weight
6.1.1 Hot-rolled steel bars
6.1.1.1 The dimensions and theoretical weight of hot-rolled round steel and square steel shall comply with the provisions of Table A.1.
6.1.1.2 The dimensions and theoretical weight of general-purpose hot-rolled flat steel shall comply with the provisions of Table A.2.
6.1.1.3 The dimensions and theoretical weight of hot-rolled flat steel for tools and dies shall comply with the provisions of Table A.3.
6.1.1.4 The dimensions and theoretical weight of hot-rolled hexagonal steel and hot-rolled octagonal steel shall comply with the provisions of Table A.4.
6.1.1.5 Agreed by the supplier and the purchaser and indicated in the contract, hot-rolled steel bars of other dimensions not specified in Tables A.1 to A.4 may also be supplied.
6.1.1.6 Hot-rolled steel bars should be delivered by actual weight. Agreed by the supplier and the purchaser and indicated in the contract, they may also be delivered by theoretical weight.
6.1.2 Forged steel bars
6.1.2.1 The dimensions and theoretical weight of forged round steel and square steel shall comply with the provisions of Table A.1.
6.1.2.2 The dimensions and theoretical weight of forged flat steel shall comply with the provisions of Table A.5.
6.1.2.3 Agreed by the supplier and the purchaser and indicated in the contract, forged steel bars of other dimensions not specified in Tables A.1 and A.5 may also be supplied.
6.1.2.4 The theoretical weight of forged steel bars with nominal dimensions exceeding the range specified in Tables A.1 and A.5 shall be determined through negotiation between the supplier and the purchaser.
6.1.2.5 Forged steel bars should be delivered by actual weight. Agreed by the supplier and the purchaser and indicated in the contract, they may also be delivered by theoretical weight.
6.1.3 Cold-drawn steel bars
6.1.3.1 The dimensions and theoretical weight of cold-drawn round steel, square steel and hexagonal steel shall comply with the provisions of Table A.6.
6.1.3.2 Agreed by the supplier and the purchaser and indicated in the contract, cold-drawn steel bars of other dimensions not specified in Table A.6 may also be supplied.
6.2 Tolerance of dimensions
6.2.1 Hot-rolled steel bars
6.2.1.1 The tolerances of dimensions of hot-rolled round steel and square steel shall comply with the provisions of Table 1. The dimension tolerance group may comply with the corresponding product standard or be indicated in the order contract; if not indicated in the product standard or contract, the tolerance of Group 3 shall apply.
Table 1 Tolerances of dimensions of hot-rolled round steel and square steel
Contents of GB/T 702-2026
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Sectional shape
6 Sectional dimensions, weight and tolerances
7 Length and tolerances
8 Shape
Annex A (Normative) Dimensions and theoretical weight of steel bars
