Recommended limits are applicable to parts measured in the unrestrained condition flatness tolerances for metal stamping.
Flatness tolerance sheet metal.
Sheet metal guage tolerances.
T351 t451 t651 t851 t7351 and t7651.
In general sheets 60 wide and under are to be no more than out of flat when laid on a flat surface.
Sheet metal is often controlled with flatness tolerance.
Parts may be measured in either unrestrained or restrained conditions.
During the rolling process the rollers bow slightly which results in the sheets being thinner on the edges.
For material longer than 10 the variation in flatness for any 10 feet of length should not exceed the amount shown.
Flatness tolerance is the permissible distance between two parallel planes within which all irregularities of a given surface must lie.
Since rolled alloys also levels this product we work to the mill tolerances.
Note any feature requirement comes with price tag on it.
4 for widths over 6 ft these tolerances alloy for any 6 ft of total width.
Flatness tolerances for sheet are published only for full size sheets.
Plates can be out of flat for a number of reasons.
This not only control the rock but also the allowable mechanical stress which deform the shape of the sheet metal like in case of parts that will be welded thermal stress bolted bending due to too much torque or screwed.
For material 10 or less in length variation should not exceed amount shown in table.