Dimensional tolerance

The dimensional tolerance of stamping parts is specified in GB / t13914-2002 dimensional tolerance of stamping parts. Dimensional tolerances are specified for flat and formed parts respectively. The dimensional tolerance value of stamping parts is related to the dimensions of stamping parts and plate thickness, on the other hand, it is related to the accuracy level.

Dimensional tolerance of flat stamping parts: it is divided into 11 grades, represented by ST1 to st11, where st represents dimensional tolerance of flat stamping parts, and the tolerance grade code is represented by Arabic numerals. From ST1 to st11, the accuracy level decreases in turn.

Dimensional tolerance of forming stamping parts: the forming stamping parts are divided into 10 accuracy levels, which are expressed by FT1 to ft10, where ft represents the dimensional tolerance of forming stamping parts, and Arabic numerals represent the tolerance level. From FT1 to ft10, the accuracy level decreases in turn.

Limit deviation of stamping parts: the deviation of hole size from the bottom is 0, and the upper deviation is the lower deviation plus the dimensional tolerance; the upper deviation of shaft size is the basic deviation, and the value is 0, and the lower deviation is the upper deviation minus the dimensional tolerance. For hole center distance, hole edge distance, length and height of bending and drawing, the upper and lower deviation shall be half of the dimensional tolerance.