Sheet Metal Stamping Tolerances

Shearing is a process for cutting sheet metal to size out of a larger stock such as roll stock.

Sheet metal stamping tolerances.

Tolerance which can be defined as the permissible limit or limits of variation in the manufacturing process is applied throughout the development of a metal stamping. As raw material sheet metal has behavioral weirdness. Where a feature has multiple bends tolerance stack up should be analyzed and allowed for. A part design can present tolerance as an upper limit and a lower limit or an allowable range.

Sheet metal guage tolerances during the rolling process the rollers bow slightly which results in the sheets being thinner on the edges. Shearing material thickness range varies from 0 125 mm to 6 35 mm 0 005 to 0 250 in. For this reason tolerancing of features placed at the outer end of a form should take the angular tolerance of the bend and the distance from the bend into consideration. Progressive tooling is ideal for complex parts that require several steps to be completed from the flat strip to the finished part.

Angular tolerances of 1 degree or so should be allowed on bends of any angle. The tolerances shown are well suited to the progressive stamping process and thus ensure quality and cost effective parts. You may see a dimension s tolerance written with the symbol. In order to achieve perfect flatness you first need to know the flatness tolerance for the surface you re working with.

Some of that weirdness stress in particular is relieved during manufacturing. The tolerances in the table and attachments reflect current manufacturing practices and commercial standards and are not representative of the manufacturer s standard gauge which has no inherent tolerances. Moreover engineers must consider the fabrication process that will convert the sheet metal into a part and the die accuracy and its wear during the punching operation to ensure tolerances are. Flatness tolerances for metal stampings free chart when flattening for your metal stamping project first need perfect flatness that condition which exists when all points on a surface lie in the same plane.

The resulting bend angle variation and sometimes the required adjustment to the flat layout contributes to the reason that machined parts typical tolerance of 0 002 in can routinely have tighter tolerances than precision sheet metal parts typical tolerance of 0 010 in.