Dimensioning Formed Sheet Metal

Trilux manufactures more than 9 000 sheet metal products including intricate luminaire bodies that form the basis of a commercial lighting unit.

Dimensioning formed sheet metal. Fortunately hems are rarely specified on tight tolerance flanges. Hem measurement forming hems is one of those aspects of sheet metal that is very operator dependent. Form height to thickness ratio to determine the minimum form height for sheet metal use the following formula. I think this is the better way because you can acquire your cutting length without a flat pattern by adding the inside lengths fold allowance.

Their standard measuring process involved traditional equipment visual exams conducted by floor operators and templates that were often created in house. Since each metal fabricator has its own tooling bend factors and equipment to develop the flat blank it is better to fully dimension to formed views for that manufacturer. In a sheet metal design specifying hole sizes locations and their alignment is critical. Your manufacturer may not be able to match dimensions when creating the actual sheet metal part due to tooling and equipment limitations.

When producing drawings of sheet metal components i dimension from inside the flange walls. D 2 5t r see below the height can be less but it required secondary operations and is far more costly. Sheet metal is one of the shapes and forms metal can be bought in. 5 edge distortion an exaggerated example of edge deformation is pictured in figure a below.

Hit it softer or harder than necessary and the flange dimension changes. Sheet metal is any metal that has a thickness in between 0 5 6 millimetres. One needs to check that these factors are consistent with the tooling that will be used in manufacturing. Millimetres mils gauge foils sheets and plates are pretty much the same with the only difference being in thickness.

And also find you fold centers more easily. Hit the hem just right and the numbers work. Some critical dimensions that need to be considered when setting up sheet metal in cad software are sheet metal thickness the k factor and bend radius.