This standard specifies the dimensions, shape, quality and allowable deviation of the finished silver bright steel, and specifies the technical requirements for the delivery status and surface quality of the silver bright steel. This standard is applicable to the surface finished silver bright round steel and steel wire with a diameter of 0.6~80mm. GB/T 3207-1988 Silver Bright Steel GB/T3207-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Bright steel
Bright steel
The dimensions and permissible deviations in this standard adopt the values ​​of the international standard 1SO/R286-1962 "ISO limits and fit tolerances and deviations", which is consistent with the provisions of GB1800-79 "Tolerances and fits". 1 Subject content and scope of application
UDC669.14
GB 8207-88
Replaces GB 3207-82bzxZ.net
Part 1: General,
This standard specifies the dimensions, shape, weight and permissible deviations of the finished silver bright steel, and specifies the technical requirements for the delivery status and surface quality of the silver bright steel.
This standard is applicable to the surface finished silver bright round steel and steel wire with a diameter of 0.6 to 80 mm. 2 Reference standards
GB2101 General provisions for acceptance, packaging, marking and quality certification of steel GB2103 General provisions for acceptance, packaging, marking and quality certification of steel wire 3 Delivery status and code
3.1 There are four delivery statuses of bright steel, and their codes are as follows: Polishing—P
Grinding—M
Grinding—ML
Cutting—Q
3.2 The polishing status should be made by polishing after grinding, cutting or cold drawing. 3.3 The grinding status and cutting status should be made by grinding or cutting after cold drawing or hot treatment. 3.4 The grinding and drawing status should be made by cold drawing or after grinding and cutting. 3.5 The delivery status of bright steel should be indicated in the contract. If not indicated, it shall be delivered in the cutting or polishing status. 4 Dimensions, shape and allowable deviations 4.1 Sectional shapes and marking symbols are as shown in the figure below. Approved by the Ministry of Metallurgical Industry of the People's Republic of China on November 25, 1988 and implemented on January 1, 1990 GB 3207-88 4.2 The diameter, cross-sectional area and theoretical weight of round steel are listed in Table 1 Table 1 Round steel diameter Cross-sectional area Theoretical weight kg/10 mm True diameter d of national steel Cross-sectional area Note: The theoretical weight in the table is calculated based on a density of 7.85 kg/dm. Theoretical weight kg/10 mm t
Steel diameter
Cross-sectional area
Theoretical key
kg/1000m
12 500
15 420
17 300
18 600
22 200
26 000
34 700
GB3207-88
4.3 Round steel with intermediate sizes can be supplied, but intermediate sizes are not recommended. 4.4 Diameter tolerance
4.4.1 The diameter tolerance of bright steel shall comply with the provisions of Table 2. Table 2
0, 6 ~ 1. 0
23. 0~6,0
>10~18
18 ~ 30
3～50
8 (h8)
-0,033
Allowable deviation level
Allowable deviation
- 0, n24
10 （h10）
-0,100
! (hi)
4.4.2 The allowable deviation of the diameter in the cutting or grinding state is limited to the part with a distance of more than 100mm from the end. 4.4.3 According to the requirements of the purchaser, silver bright steel with positive deviation or negative deviation can also be supplied, but its tolerance range should not exceed the values ​​specified in the table. 4.4.4 The tolerance level of diameter of bright steel shall be specified in the contract. If not specified, it shall be delivered as Grade 11. 4.5 Length and tolerance
4.5.1 The normal length shall comply with the provisions of 3.
Diameter of two steels
>1～3
>3 - 9
9 ~ 30
GB 8207-88
Normal length
Latex ≥1.5
Forging ≥0.7
4.5.2 Fixed length and multiple length
The fixed length or multiple length of bright steel shall be specified in the contract. The tolerance of its length shall be +50mm when the diameter does not exceed 30mm and +60mm when the point diameter exceeds 30mm.
According to the requirements of the purchaser, the tolerance of the fixed length of bright steel may not exceed +25mm. 4.6 Appearance
4.6.1 Bright steel is usually supplied in straight bars. Bright steel with a diameter less than or equal to 10 μm may be supplied in coils. 4.6.2 The ovality of the bright steel shall not exceed half of the allowable tolerance of the diameter. 4.6.3 Curvature
4.6.3.1 Bright steel supplied in straight bars shall be straight and shall not have obvious spiral distortion. 4.6.3.2 The curvature of bright steel shall comply with the provisions of Table 4. Table
. 30
Various states
(Except grinding and cold drawing and polishing)
Grinding and cold drawing and polishing
Various states
Hyaline curvature
Not large"
Total curvature
Not large
Heavy steel length 1.0%
0.2% of the length of the material
0.1% of the length of the steel
4.6. The end of the bright steel should be cut straight without burrs. According to the requirements of the user, the end can be chamfered for delivery. 4.7 Marking example
In the GB3206 standard, the 45 steel in the soft state and the silver-bright steel with a diameter of 4.0mm and a polished state with an allowable deviation of 11 are marked as follows: 5 Technical requirements
GB 32078B
Silver-bright steel-4.0-M-11-GB_3207
45-R-GB3206
5.1 The chemical composition of silver-bright steel shall comply with the relevant product standards. 5.2 The physical and chemical properties of silver-bright steel shall comply with the relevant product standards. 5.3 The mechanical and process properties of silver-bright steel shall fluctuate by 10% or make supplementary provisions compared with the relevant product standards. 5.4 There shall be no decarbonization layer on the surface of silver-bright steel. 5.5 Surface quality: The surface of silver-bright steel shall be smooth, bright and clean, and there shall be no external defects such as cracks, hairline, folds, scratches, concave surfaces, grains, rust and oxide scale. However, individual slight scratches, spiral patterns or lubrication marks with a depth not exceeding half of the diameter tolerance are permitted.
6 Test methods
6.1 The surface quality of the bright steel is checked by hand. 6.2 The size and shape of the bright steel are measured with measuring tools of corresponding accuracy: 6.3 The mechanical properties and process properties of the bright steel are tested according to the test methods specified in the corresponding product standards. 7 Inspection rules, packaging marks and quality certificates 7.1 Check the surface quality, shape, size and allowable deviation of each piece (or plate) of bright steel. 7.2 Bright steel should be supplied in boxes and can be supplied in bundles with the consent of the purchaser. For diameters of less than 15mm or equal to 15mm, they should comply with the provisions of GB2103; for diameters greater than 15mm, they should comply with the provisions of GB2101. 7.3 The packaging marks and quality certificates of bright steel should comply with the relevant provisions of GB2103 and GB2101. Additional remarks:
This standard was drafted by the person in charge of Dalian Steel.
The main drafters of this standard are Xinhong and Guanghong Zhao. From the implementation of this standard, the original Ministry of Metallurgical Industry Standard YR247-61 "Silver-filled Steel Technical Conditions" will be invalid. This standard water grade mark GB 3207-88I
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.