Stamped Sheet Metal Tolerances

Shears are used as the preliminary step in preparing stock for the stamping processes or smaller blanks for cnc presses.

Stamped sheet metal tolerances.

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. Most experienced metal stamping manufacturers should be able to achieve 010 for most features. This method works well for the bowing up problem shown in figure 1. Shearing material thickness range varies from 0 125 mm to 6 35 mm 0 005 to 0 250 in.

In fact research suggests that manufacturers spend 30 to 50 of their time. The tolerances shown are well suited to the progressive stamping process and thus ensure quality and cost effective parts. Typical stamping speeds do vary however many high production stamping manufacturers are capable of 30 to 80 stamping stokes per minute. The dimensional tolerance ranges from 0 125 mm to 1 5 mm 0 005 to 0 060 in.

Commonly used flatness tolerances for metal stamping laser and turret are shown below. Engineers designing sheet metal enclosures and assemblies often end up redesigning them so they can be manufactured. The rule of thumb in stamping design is to leave a minimum of 1 1 2 times material thickness between trimmed or perforated features. Over 300 to 1000 incl.

Over 1 to 4. Over 1000 to 3000 incl. From 0 to 1. Stippling the outside bend radius.

Below are dimensions and tolerances typical of stamped metal components. Tolerance class nominal length on shorter side 100 or less over 100 to 300 incl. Dimensional tolerances of metal parts manufactured by stamping should be carefully considered. For the same reason perforated or trimmed features that are placed too close to each other or the material edge tend to roll the material between producing a distorted or thinned edge.

Sheet metal guage tolerances during the rolling process the rollers bow slightly which results in the sheets being thinner on the edges. Of course exceptions apply. 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.