- Custompartnet Calculator Bend Allowance
- Tubing Bend Allowance Calculator
- Bend Allowance Calculator For Stainless Steel
- Bend Allowance Calculator
Bend Allowance Calculator Here's some info to decode what this means: Bend Allowance is a compensation for what happens to the material as it's stretched. Correct calculation of an unfolded part for a press brake. Understanding the relation between V opening, radius, bending allowance, and K factor is very important to better calculate an unfolded part before cutting the flat blank from the sheet metal. Bend allowance - The length of the neutral axis between the bend lines, or in other words, the arc length of the bend. The bend allowance added to the flange lengths is equal to the total flat length. Bend deduction - Also called the bend compensation, the amount a piece of material has been stretched by bending. The value equals the difference. Radiused Bend Sharp Bend See the Hand Tube Bender Manual, MS-13-43, for more To achieve information. The desired bend, mark the tubing as follows: P1 90° = 3 in. To determine the location of the bend mark for a subsequent bend, add the new 5/16 section leg length to the previous (3.0) bend mark location, then subtract the adjustment (gain) of.
Understanding Bend Deductions
INTRODUCTION
Sheet metal fabrication, and specifically, precision sheet metal fabrication is an excellent way to create and built robust products by means of cutting, forming, and assembling processes. Projects are generally designed or modeled and then sent to fabrication shops to bid on, and if won, fabricated to print. Often times, parts are not designed with best practices around sheet metal fabrication in mind requiring sheet metal shops to do a lot of work behind the scenes, getting prints ready for production using standard fabrication processes. One topic rarely covered at length and seems to create the most confusion is around Bend Deductions and consequently Bend Allowances.
BEND DEDUCTIONS
Considering the Bend Deduction and Bend Allowances is a critical first step in designing sheet metal parts as it affects nearly every following step in the fabrication process. More so, it will allow you to achieve the correct size and dimensions needed in the flat pattern. The flat pattern is what the part looks like before any bends have happened. The lengths in the flat pattern will be different from in the bent state. This is because metal material when formed in a bending process is both stretched and compressed depending on the thickness and the type of material. Intuit quickbooks pro 2016 r9 v17.1.8 for mac work with high sierra.
The Bend Deduction BD is defined as the difference between the sum of the flange lengths (from edge to the apex) and the initial flat length. In other words, the material you will have to remove from the total length of the flanges in order to arrive at the proper length in the flat pattern. In the example below, the part has flange lengths of 2' and 3' with an inside radius of .250' at 90° will have a length of 5'. When the Bend Deduction is calculated we find that it equals .293' in length. In order to develop the flat pattern, we will subtract .293' from 5' to arrive at 4.707'. The image below shows the close relation between Bend Deduction and Bend Allowance.
BEND DEDUCTION FORMULA
The Bend Deduction Formula takes into account the geometries of bending and the properties of your metal to determine the Bend Deduction. Values you will need to know will include your material thickness (MT), the Bend Angle (B<), the Inside Radius (IR), and the K-Factor (K). When entering the Material Thickness, use the decimal form in place of the gauge number. For your convenience, we have provided a material thickness chart, here: Material Thickness Guide. To determine the Bend Angle properly you must use the complementary angle of the part feature. It is important to convert the included angle to the complimentary angle before you perform the calculation. The Inside Radius will be the finished radius of the included angle. Lastly, the K-Factor is a property of the material substrate you are bending. This property reflects how the material stretches when formed.
Do not be intimidated by the length of the formula for Bend Deduction. It is long because it solves for the Out Side Set Back (OSSB) as well as the Bend Allowance.
If the Out Side Set Back (OSSB) and Bend Allowance (BA) are available then the Bend Deduction Formula is considerably shorter.
BEND DEDUCTION CHART
Bend deduction can easily be confused with bend allowance so it is important to understand the difference and when each value is needed. Creating flat patterns in sheet metal part drawings becomes easy once familiarized with each of these concepts. One key to success in speeding up the process of finding these values id to use a chart with standard values based on material substrates and thickness. We use Solid Works at Meta Fab but other software packages are available that easily help figure the bend deduction or bend allowances.
Sheet metal bending and forming is not always going to be the same in each fabrication shop. The biggest variation in fabrication comes from the material thickness itself. Protective coating, variation in the alloy and thickness as well as many other factors all add up to give you bend deductions which are unique to your processing methods. The chart below is a good starting point for most sheet metal processing applications and may not require many changes. However, if you are dedicated to precision fabrication then use the excel file below and plug in your own data to tailor it to your operations.
The below Excel chart is for even-numbered material gauges 8 through 22 and has a default K-Factor of .448 for each. You can easily modify the Material Thickness, Inside Radius, and K-Factor for each thickness at the top of each column. This chart is for reference only – you should always verify against your process for better results.
CONCLUSION
Bend Deductions are the first and more critical aspects when working with fabricated sheet metal. 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. We hope you've enjoyed this write up and found it useful. Check back for more articles around press brakes and sheet metal forming.
Custompartnet Calculator Bend Allowance
K Factor in sheet metal bending is a constant used to calculate sheet metal flat length or Flat-pattern. Mathematically k factor value is equal to the ratio of position of the neutral axis and sheet thickness. In this article, we will discuss sheetmetal bend deduction, bend allowance, K-factor, Y-factor, and sheet metal flat pattern calculations.
To understand what is K Factor? firstly we need to understand why we need K-Factor? what are bend allowance and bend deduction in sheet metal parts?
Table of ContentsTubing Bend Allowance Calculator
Why do we need K Factor during Sheet Metal Bending
Sheet metal bending is a forming operation where sheets are deformed plastically to change their shape. During sheetmetal bending, the material is stressed beyond its yield strength but below the ultimate tensile strength.
After bending a sheet metal part, the total length of sheet metal is more than the flat length. This change in length can be represented as bend deduction or bend allowance. This bend allowance and bend deduction are calculated using a constant known as the K factor or Y factor.
What is Bend Deduction in Sheet Metal?
During sheet metal bending, the inside surface of the bend is compressed and the outer surface is stretched. Which increases total outer surface area. In other words, after bending, the total sheet-metal part length (A + B) will be greater than the sheet metal Flat Length.
Bend Allowance Calculator For Stainless Steel
Mathematically
Bend Deduction = Total Sheet Metal Bend Length (A+B) – Bend Length
In the above image, this increase in total sheet metal length is represented by bend deduction that needs to be compensated during sheet metal blank size calculations.
Bend Deduction Calculations in Sheet Metal Parts
Total bend deduction in sheet metal parts can be calculated by using the following formula:
Bend Allowance Calculator
