Should be subtracted from the flat pattern so the formed part arrives at the desired dimensions.
Bend deduction sheet metal.
The bend deduction is the amount the sheet metal will stretch when bent as measured from the outside edges of the bend.
If missed it will wreak havoc on your formed parts done well and you ll have a precise measurement you and your clients will be happy with.
Bend deductions are the first and more critical aspects when working with fabricated sheet metal.
With this free online tool we quickly get the sheet metal bend deduction and therefore the sheet metal blank initial flat length from the finished part measurements.
When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.
The bend radius refers to the inside radius.
Understanding the bend allowance and consequently the bend deduction of a part is a crucial first step to understanding how sheet metal parts are fabricated.
The bend deduction formula takes into account the geometries of bending and the properties of your metal to determine the bend deduction.
The material thickness will be measured in decimal form not by the gauge number.
You only have to insert interior angle flange lengths k factor inside radius and material thickness.
As this happens you gain a small amount of total length in your part.
This is simulated on the part shown above by the section shown in red.
Sheet metal bend deduction chart pdf sheet metal bend deduction chart excel conclusion.
You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.
The bend deduction of means that the material is expected to stretch by that amount during the course of bending.