Dimensioning Formed Sheet Metal

Hem measurement forming hems is one of those aspects of sheet metal that is very operator dependent.

Dimensioning formed sheet metal.

My boss dimensions from outside the flange walls and thinks this is the. Millimetres mils gauge foils sheets and plates are pretty much the same with the only difference being in thickness. Fortunately hems are rarely specified on tight tolerance flanges. 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. 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. In a sheet metal design specifying hole sizes locations and their alignment is critical.

When producing drawings of sheet metal components i dimension from inside the flange walls. And also find you fold centers more easily. Their standard measuring process involved traditional equipment visual exams conducted by floor operators and templates that were often created in house. Hit it softer or harder than necessary and the flange dimension changes.

Hit the hem just right and the numbers work. 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. Sheet metal is any metal that has a thickness in between 0 5 6 millimetres.

D 2 5t r see below the height can be less but it required secondary operations and is far more costly. 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. One needs to check that these factors are consistent with the tooling that will be used in manufacturing.