Sheet Metal Flatness Tolerance

The tolerances shown are well suited to the progressive stamping process and thus ensure quality and cost effective parts.

Sheet metal flatness tolerance.

Table a2 8 permitted variations in flatness of cold rolled wide coil processed product as cut lengths. Parts may be measured in either unrestrained or restrained conditions. Recommended limits are applicable to parts measured in the unrestrained condition flatness tolerances for metal stamping. The flatness tolerance of of strip sheet plate and cut length shall not exceed 10mm for normal cases and 7mm where a special tolerance fs is required for length 3000mm and 12mm for normal cases and 8mm where a special tolerance fs is required for length 3000mm.

Since rolled alloys also levels this product we work to the mill tolerances. Below are dimensions and tolerances typical of stamped metal components. Sheet metal is often controlled with flatness tolerance. In general sheets 60 wide and under are to be no more than out of flat when laid on a flat surface.

Note any feature requirement comes with price tag on it. 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. 4 for widths over 6 ft these tolerances alloy for any 6 ft of total width. The flatness control c defines how much a surface on a real part may vary from the ideal flat plane.

Tolerances of 010 should be considered minimum. Tolerance below apply to the following alloys. 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. Bend allowance equation and calculator.

Sheet metal gauge size chart. Flatness tolerance is the permissible distance between two parallel planes within which all irregularities of a given surface must lie. Plates can be out of flat for a number of reasons. T351 t451 t651 t851 t7351 and t7651.

The distance between the parallel planes is the stated flatness control tolerance value. 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. Tight tolerances raise the cost of manufacturing significantly. Sheet metal guage tolerances during the rolling process the rollers bow slightly which results in the sheets being thinner on the edges.

Practical tolerances vary according to the design requirements. The flatness tolerance zone is the volume between two parallel planes. Flatness tolerances for sheet are published only for full size sheets. Sheet metal tolerances should not be tighter than necessary to make the part functional.

Progressive tooling is ideal for complex parts that require several steps to be completed from the flat strip to the finished part. 253 330 333 304 309 316 321 347 410 446 2205 2507 2101 17 4 17 5 800 tolerances listed were taken from astm a480 reference only cold rolled coil.