Flatness Tolerance For Sheet Metal

Since rolled alloys also levels this product we work to the mill tolerances.

Flatness tolerance for sheet metal. The distance between the parallel planes is the stated flatness control tolerance value. Sheet metal tolerances should not be tighter than necessary to make the part functional. 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.

Note any feature requirement comes with price tag on it. Flatness tolerances listed are of roller leveled sheets or plates with no or minimum margins. Maximum difference between aa and bb up thru 12 over 12 3 32 x width ft 2 9 64 x width ft 2 5 64 x width ft 2 7 64 x width ft 2. The flatness control c defines how much a surface on a real part may vary from the ideal flat plane.

In general sheets 60 wide and under are to be no more than out of flat when laid on a flat surface. For sheet metal parts iso 27 68 mk is used. Flatness tolerance is always less than the dimensional tolerance associated with it. As per design requirements and manufacturing capability tolerance class is defined.

And for machined components iso 27 68 fh can be used. Flatness tolerance is the permissible distance between two parallel planes within which all irregularities of a given surface must lie. For material 10 or less in length variation should not exceed amount shown in table. Linear tolerances should be held as loose as possible.

Specified width ft. Squareness tolerances flat sheet and plate. 0 0129 0 33 aluminum sheet metal tolerances table chart. Mm 48 1 219 in.

Tolerances of 010 should be considered minimum. Tight tolerances raise the cost of manufacturing significantly. In the above example m and k has defined the tolerance class. Sheet metal is often controlled with flatness tolerance.

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 zone is the volume between two parallel planes. Practical tolerances vary according to the design requirements.

The flatness tolerance references two parallel planes parallel to the surface that it is called out on that define a zone where the entire reference surface must lie. General tolerance iso 2768 does not specify where to use these tolerances. Up thru 3 over 3 allowable difference in length of diagonals inches.