Calculating a sheet metal flat pattern in Excel is a thing of the past – instead, calculate your sheet metal flat pattern online. Determine the flat pattern of your bent sheet metal based on the finished dimensions. Please note that the calculated values are intended as guide values only.
Note: An approximate dimension should be used, as measurements may vary depending on the manufacturing process, material and other individual factors. Using an approximate dimension helps ensure an optimal result, even when minor production tolerances occur.
The neutral axis of the material plays a key role in sheet metal flat pattern development. This is the area within the material that neither stretches nor compresses during bending. It is located between the stretched fibres on the outside and the compressed fibres on the inside of the bend.
The position of the neutral axis depends largely on the internal bend radius and the thickness of the material. Various methods can be used to calculate its position. One simple approach is to use a table showing the position of the neutral axis as a function of the internal radius and material thickness:
| Internal radius | Factor × thickness |
| 0.2 | 0.347 × thickness |
| 0.5 | 0.387 × thickness |
| 1 | 0.421 × thickness |
| 2 | 0.451 × thickness |
| 3 | 0.465 × thickness |
| 4 | 0.470 × thickness |
| 5 | 0.478 × thickness |
| 10 | 0.487 × thickness |
Example: If the internal bend radius of a 2 mm thick sheet is 4 mm, the calculation is: 0.470 × 2 = 0.94. This is the position of the neutral axis.
L-shape
Formula: Flat side A + Flat side B + π/2 × (Internal radius + neutral axis)
U-shape
Formula: Flat side A + Base + Flat side B + π/2 × (2 × Internal radius + neutral axis)
Sheet metal is a “living” material, and the bending process depends on many factors, including material thickness, quality and type, die width, and more. For this reason, we recommend having a small sheet metal sample produced before manufacturing a large series. We also, of course, check the dimensions before and after bending.
This allows you to adjust the flat pattern based on your own measurements and under the most controlled conditions possible. Visit our website to try our calculation tools directly and make your production processes more efficient.
Flat pattern development is a crucial factor in the production of bent perforated metal sheets. In the past, these calculations had to be carried out laboriously in Excel, often resulting in errors and wasted time.
Today, however, there is a more efficient solution. With our user-friendly online tool, you can quickly and easily determine the flat pattern of your bent sheet metal based on the finished dimensions. The calculated values serve as guide values, providing a reliable basis for your further planning.
Explore our other calculation tools and try them out directly.
