I believe everyone will encounter this situation when buying stainless steel plates. The plates they bought are obviously 6mm thick, but the actual thickness is not there. This is the tolerance of stainless steel plates. Tolerance is the recognized allowable thickness deviation, and it is also the "hidden rule" of the stainless steel industry. Because during the rolling process of steel mill machinery, the rollers are slightly deformed when heated, resulting in deviations in the thickness of the rolled stainless steel plates. Generally, the middle is thicker and the sides are thinner. Therefore, the actual thickness often does not reach the theoretical thickness. For example, the actual thickness of a board with a standard thickness of 5mm is only 4.7mm.

   In China, tolerances are often negative tolerances. Of course, there are positive tolerances, but they are very few. When buying and selling stainless steel plates, they are usually calculated based on the theoretical thickness, which is why the theoretical price is lower than the weighing price. Tolerances vary by size, and prices are also different. Larger tolerances are cheaper. For example, for a stainless steel plate with a standard thickness of 6mm, if the actual thickness is less than 5.5mm, it is a large tolerance.