GB 908-87 Steel Round and Square Bars
This standard outlines the dimensions, shape, weight, and allowable tolerances for round and square steel bars.
Dimensions
The general dimensions of steel round bars with a maximum diameter of 250 mm, and the general dimensions of square bars with a maximum side length of 600 mm are stated in the standard. The top and bottom surfaces of round and square bars are required to be plane and parallel, and the bars should be ground or polished if specified.
Shape
The standard states that the round and square bars should be of a cylindrical or rectangular shape and should have a uniform cross-section throughout the length of the bar.
Weight
The standard states that the weight of the round and square bars should correspond to the nominal cross-sectional area of the bar and should take into account the tolerance for thickness.
Allowable Tolerances
The standard states that the allowable tolerance should be within ±2.5% of the nominal cross-sectional area of the bar, and the allowable tolerance should not exceed ±3% of the nominal cross-sectional area of the bar. The unit length of the round and square bars should be within ±2.5% of the specified length.
Conclusion
This standard outlines the dimensions, shape, weight, and allowable tolerances for round and square steel bars. The dimensions and shape should conform to the requirements stated in the standard, and the weight should correspond to the nominal cross-sectional area of the bar. The allowable tolerance should be within ±2.5% of the nominal cross-sectional area of the bar and the unit length of the round and square bars should be within ±2.5% of the specified length.
Ensuring that these requirements are met will result in the production of steel bars that conform to the standards set by GB 908-87.
