GB/T 9788-1988 Hot Rolled Unequal Angles: Dimensions, Shape, Mass and Permissible Deviations
This standard applies to hot rolled unequal angles for use in structural engineering.
The size tolerance for dimensions such as width (tolerance for the range of ± 0.4 to ± 5 mm) and length shall be in accordance with GB/T 699 “Size Tolerances for Hot Rolled Steel Sheets and Strips”. The allowable deviation of mass shall be in accordance with Annex A of GB/T 9788.
The hot rolled unequal angles should have the following shapes:
Side : They should be smooth, regular and symmetrical;
Corner : The external corner should be right-angled and symmetrical;
Chamfer : The chamfer should be straight and its depth should not exceed the allowable limit in Annex B.
The allowable deviations of dimensions and mass per meter of a cross section should conform to the provisions of Annex B.
Deliverables of hot rolled unequal angles should meet the requirements of Table 1:
1. The length of the unequal angle should be within the range of 2m to 12m;
2. The surface of the angle should be free from defects that can affect its usability;
3. The ends of the angle should be cut square and free from chipping or burrs;
4. The average mechanical properties of hot rolled unequal angles should meet the requirements of GB/T 700 for carbon structural steel.
This standard is applicable to hot rolled unequal angles for use in structural engineering. It should be noted that hot rolled unequal angles with a unit mass greater than 80 kg/m should be produced according to GB/T 1591 “Hot Rolled Steel Boules”.
The annex of this standard contains explanatory supplementary notes to the provisions of this standard. This information contains model checking rules as well as inspection considerations.
This standard was formulated in 1988 and came into force on December 1st of the same year. This standard will be subject to periodic changes according to the technological advancement of this industry.
This standard is maintained by the Technology and Quality Bureau of China Metals.
