Flatness Tolerance Sheet Metal

For material 10 or less in length variation should not exceed amount shown in table.

Flatness tolerance sheet metal. 4 for widths over 6 ft these tolerances alloy for any 6 ft of total width. Flatness tolerance is the permissible distance between two parallel planes within which all irregularities of a given surface must lie. Sheet metal guage tolerances. Parts may be measured in either unrestrained or restrained conditions.

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. Plates can be out of flat for a number of reasons. Flatness tolerances for sheet are published only for full size sheets. Flatness tolerances listed are of roller leveled sheets or plates with no or minimum margins.

In general sheets 60 wide and under are to be no more than out of flat when laid on a flat surface. For material longer than 10 the variation in flatness for any 10 feet of length should not exceed the amount shown. 5 short span flatness is the deviation from flat over full span for spans 2 ft and less 2 tx51 is a general designation for the following stress relieved tempers. Recommended limits are applicable to parts measured in the unrestrained condition flatness tolerances for metal stamping.

Sheet metal is often controlled with flatness tolerance. During the rolling process the rollers bow slightly which results in the sheets being thinner on the edges. T351 t451 t651 t851 t7351 and t7651.