Dimensioning Formed Sheet Metal

Hit it softer or harder than necessary and the flange dimension changes.

Dimensioning formed sheet metal.

When producing drawings of sheet metal components i dimension from inside the flange walls. 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. It is always better to specify hole diameters that are greater than the sheet s thickness t. My boss dimensions from outside the flange walls and thinks this is the.

And also find you fold centers more easily. Sheet metal is one of the shapes and forms metal can be bought in. Hit the hem just right and the numbers work. Form height to thickness ratio to determine the minimum form height for sheet metal use the following formula.

In a sheet metal design specifying hole sizes locations and their alignment is critical. Sheet metal is any metal that has a thickness in between 0 5 6 millimetres. Trilux manufactures more than 9 000 sheet metal products including intricate luminaire bodies that form the basis of a commercial lighting unit. Your manufacturer may not be able to match dimensions when creating the actual sheet metal part due to tooling and equipment limitations.

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. There are other measurement units used to categorise metals by thickness though. 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. Fortunately hems are rarely specified on tight tolerance flanges.

One needs to check that these factors are consistent with the tooling that will be used in manufacturing. D 2 5t r see below the height can be less but it required secondary operations and is far more costly. 5 edge distortion an exaggerated example of edge deformation is pictured in figure a below.