The Difference in Allowable Deviations for Hot Rolling and Cold Rolling Thin Plates
Thin plates are extensively used in a variety of applications because they offer stability, strength and can be fabricated into objects with more precision than thicker plates. To ensure the desired characteristics of the thin plates, the dimensions and weight of the plates must be taken into account. The allowable deviations of the hot rolling and cold rolling thin plates play an important role here.
When it comes to the tolerances of thin plates, hot rolling and cold rolling processes have their own requirements. Hot rolled thin plates should meet the requirements of ASTM A480/A480M, which stipulate that the maximum total permitted variation of the thickness must not exceed 10% of the ordered thickness for plates 0.25 or less in thickness. For plates 0.25 to 1.0 thick, a total variation of the thickness of ±1.0 will be allowed, of which the variation across the width must not exceed 1/2 of the specified width. In addition, the maximum variation of the width across the length must not be over 1/4 of the specified width. Furthermore, the tolerances of the length must also be taken into consideration. The allowable deviation of the cold rolled thin plates, on the other hand, is more restrictive. Generally, the maximum total variation of the thickness should not exceed 5.0% of the ordered thickness. The variation across the width must not exceed 1/4 of the specified width, and the maximum variation of the width across the length must not exceed 1/8 of the specified width. Also, the allowable deviation of the length should be within ±1/16 of the specified length.
The above allowable deviations for hot rolling and cold rolling thin plates have the same purpose – to ensure the desired properties of the plate. With the differences between the two specifications in mind, manufacturers must choose the appropriate process to meet their requirements. Each product has different tolerances that must be addressed. For example, some products require tighter tolerances than those of hot rolling or cold rolling. Therefore, it is important to review the tolerances specified in the requirements document before proceeding with either process.
In conclusion, although hot rolling and cold rolling thin plates have different allowable deviations, they serve the same purpose of ensuring the desired performance characteristics of the final product. Manufacturers must take the time to identify the required tolerances before making the appropriate choice of process.
