# Bend Deduction

## Bend Allowance, Bend Deduction and K-Factor Tables in SOLIDWORKS

In this series of blog posts it was discussed what different terms like Bend Allowance, Bend Deduction and K-Factor mean and how we can calculate them for a specific sheet. You can read the previous post: What are Bend Allowance, Bend Deduction and K-Factor? And the post that explains how to calculate them here. In this post you will see how to use these calculated values in order to make our own SOLIDWORKS Sheet Metal Bend Table. Bend tables and gauge tables come into play when working with sheet metal parts in SOLIDWORKS. The location where SOLIDWORKS reads these tables from is set in Options > System Options > File Locations. Select “Sheet Metal Bend Tables” or “Sheet Metal Gauge Table” to see the location where SOLIDWORKS reads the tables from. Bend Tables Bend tables were the original tables used by SolidWorks to pull Bend Deduction, Bend Allowance or K-Factor values for use in…

## Calculating Bend Allowance, Bend Deduction, and K-Factor

In my previous post I talked about K-Factor, Bend Allowance and Bend Deduction and what they mean in sheet metal design. Now let’s see how we can obtain these values for a specific sheet. As I mentioned in my last post you need to do some tests to calculate these values for a specific sheet. These tests include bending some samples and then do some measurements and calculations. Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in Figure 1. We are going to review three bending scenarios with three different bending angles; 60, 90 and 120, and we will calculate K-Factor, Bend Allowance and Bend Deduction for them. The bending tool has a radius of 30 mm which means that our Inside Bend Radius (R) is 30 mm. Let’s start with 90 degrees bend which is the most simple scenario. 90 Degrees…

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## What Are Bend Allowance, Bend Deduction and K-Factor?

In a series of posts we are going to review the most important sheet metal design terminology — Bend Allowance, Bend Deduction and K-Factor. In this post I will review what these terms mean and in the next post I will show you how to calculate and use them in SOLIDWORKS. In sheet metal bending process when metal is bent the material along the inner bend radius is going to undergo compression and the material along the outer bend radius will be stretched. The line where the transition from compression to stretching occurs is called the neutral axis or the neutral sheet. The neutral axis is where neither the material stretches nor compressed. Hence, the length of the neutral axis stay the same before and after bending operation. The location of the neutral axis varies and is based on the material’s physical properties and its thickness. It is important to know the location…

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## Sheet Metal Bend Deduction Calculations with Switching Directions

When using Bend Deductions in sheet metal, be careful when you have corners that change directions. As shown at the bottom of the blog post Sheet Metal Bend Allowance Calculations, the Bend Deduction calculation is straight forward by taking all outside dimensions then subtracting the bend deduction values for each bend. All Bends in the Same Direction Here is a simple example as a base flange with material inside the sketch. The material thickness is 0.1″. For simplicity, the Bend Deduction value has been set as 0. Therefore the calculation of the flat pattern length is: (Total Outside Dimensions) – (Bend Deduction * Number Of Bends) = (1 + 5 + 3 + 1) – (0 * 3) = 10″

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