In the cold bending forming industry, apart from thickness, the width tolerance of the sheet material is also a key factor affecting the quality of the finished product and the installation accuracy. The term "width tolerance" refers to the allowable deviation between the effective width of the formed sheet material and the designed value.

1. Definitions of Upper Tolerance and Lower Tolerance
Upper Tolerance (+): The effective width after forming is larger than the designed value. For example, if the design is 1000mm, the effective width may reach 1002mm.
Lower Tolerance (-): The effective width after forming is smaller than the designed value. For example, if the design is 1000mm, the effective width may only be 998mm.

2. The actual impact of width tolerance
When the formed sheet deviates towards the upper tolerance, the lap joint will be tighter, but the overall arrangement may "exceed" the planned coverage size, and the cumulative error will affect the total length control.
When the formed sheet deviates towards the lower tolerance, the effective width decreases, and after overlapping laying, the overall coverage area may be insufficient, resulting in increased material consumption.
Example: A corrugated sheet is designed with a width of 0.25mm (assumed). Within a width tolerance of ±0.2mm:
If it is close to the lower limit of 0.17mm, the sheet shape will appear more "loose";
If it is close to the upper limit of 0.40mm, the overall width will be slightly smaller.

3. Points for Customers to Pay Attention To
Design Basis: The plate shape is usually designed based on the following tolerances to avoid insufficient final product area.
Cumulative Error: Even if the tolerance of a single plate is only ±2mm, when dozens of plates are joined together, the overall size difference may exceed 50mm.
Acceptance Criteria: In engineering applications, it is recommended to randomly inspect the width of the formed plates and combine it with the effective width standard for rechecking.