This is a very important term.
Tolerances are generally accepted lengths or thickness deviations because it is difficult for a variety of reasons in the production of sheet metal. The actual thickness that comes out is often less than the theoretical thickness. For example, a 6 mm plate has only 5.6 mm. This is the tolerance. pipe fittings
The tolerance in the country is often negative, and there are certainly positive tolerances, but it is rare. When trading the board, it is usually calculated according to the theoretical thickness, which is why the theoretical price is lower than the weighing price. The tolerance is also the size of the price, the price is not the same, the price of large tolerance is cheap. For example, 6 mm If it is 5.5 or less, it is a big tolerance.