As i mentioned in my last post you need to do some tests to calculate these values for a specific sheet. The following illustration shows a and b, used to calculate the bend allowance. Cad tools use kfactor to calculate sheetmetal blank size. The k factor in sheet metal working is the ratio of the neutral axis to the material thickness. In sheet metal, there is a powerful bend constant known as the kfactor. Learn what a kfactor is in sheet metal forming, learn how kfactor is used, and learn how to calculate kfactor in this video. Simple threeline sketch to test our sheet metal gauge tables. Then learn how to create basic parts, with base features, flanges, and bends that add strength and connections. The setback chart is a quick way to find the setback and is useful for open and closed bends, because there is no need to calculate or find the kfactor. We will start by creating a simple sheet metal design with a threeline sketch. How to use this kfactor calculator in sheet metal reverse engineering approach step1. Sheet metal fabrication ranges from deep drawing, stamping, forming, and hydro forming, to highenergyrate forming herf to. In low carbon steel sheet metal, the minimum radius of a bend should be one.
Importance of the kfactor in sheet metal design the kfactor is used to calculate flat patterns because it is related to how much material is stretched during bending. If you follow the design advice and maintain the tolerances expressed in this article, you are more likely to end up with parts. No part of this work may be reproduced or used in any form or by any means graphic, electronic, or. Now, you may be thinking, where this k factor is used. We use 18 gauge 316 stainless steel, our solidworks is set to. Suppose that you have designed a sheet metal component for fabrication. Hence all of the sheet metal designing software use kfactor, in order to provide an accurate design of the flat pattern of the sheet metal component. Sheet metal basics sheet metal interview questions for. The solidworks application also comes with a kfactor bend table in microsoft excel format. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. The kfactor is fundamental to designing precise sheet metal. Continuing our focus on sheet metal forming, this issue of dfm guidebook focuses on design guidelines for bend relief parameters, distance between holes and bends and offset bend material when a bend is made close to an edge. When you bend sheet metal, the neutral axis shifts toward the inside.
Now lets see how we can obtain these values for a specific sheet. Therefore, when sheet metal has complex bends, consider splitting a complex bend into two parts. Let me make it clear that it is a very important term used in sheet metal design. Kfactor is actually the ratio of the offset t of the neutral axis from the inside bend and the thickness of the sheet t when a piece of sheet metal is bent. Here is an equation for the kfactor given by solidworks in the help file for bend calculation table, with no explanation. Therefore, it is not part of the standard freecad install.
It allows you to anticipate the bend deduction for a large variety of. In this article we will discuss sheetmetal bend deduction, bend allowance, kfactor, yfactor and sheet metal flat pattern calculations. Cut a sample sheet and measure its total flat length and sheet thickness in mm. Sheet metal design with the booming need to enhance the product quality and finishing, testing different metallurgy at affordable cost, sheet metal fabricators demand accurate fabrication drawings. The kfactor in sheet metal working is the ratio of the neutral axis to the material. Bending a known length of sheet metal is easy, but to calculate the bend. Many cad programs also work out bend allowances automatically by using kfactor calculations.
You may be wondering what exactly is bend allowance if youve never worked with sheet metal before. Because of the specific properties of any given metal, there is no easy way to calculate that value perfectly, hence the chart in figure 2. We are actually in the process of dialing in our solidworks sheet metal properties to match the brakematerial we are using. The kfactor is the ratio between the the neutral axis to the thickness of the material.
Having an accurate idea of your kfactor is key to designing good parts. Design methodologyapproach a dummy 3d cad model of the assemblies has been made using assembly. Similarly, the more complicated the sheet metal bending process, the more material waste may be caused. We are now ready to use these sheet metal gauge tables. Solidworks sheet metal tools are relatively straight forward, but may not be clearly understood. Then run your bend calculations using a kfactor that takes your. Sheet metal operationpart 1sheet metal design series. Calculate k factor, bend allowance and y factor for sheet metal. Design surface part as designed to fit in the car after trimming blankholder surface. Bending calculations using kfactor, bend deduction, and.
Sheet metal fabrication plays an important role in the metal manufacturing world. And, you have all the dimensions of the final component in your design. You can also use our flat pattern calculator for blank size calculation. Design for manufacturability sheet metal guidelines. Kfactor calculator for sheet metal bending smlease design. If you design your bent sheet metal parts in cad software that has a special sheet metal environment, use it. The kfactor in sheet metal working is the ratio of the neutral axis to the material thickness. Design for manufacturability sheet metal guidelines bends for the ease of manufacturing, multiple bends on the same plane should occur in the same direction. All this information is necessary when making a flat pattern for laser cutting. The location of this neutral line is referred to as the kfactor.
How to set up sheet metal gauge tables engineers rule. Most cad systems that have sheet metal design tools will allow you to input a kfactor that the software uses to calculate the unfolding to give an accurate blank, or flat pattern. Our pages on fabrication formulas, tooling terminology, and gage charts are references for the industrys engineers. To achieve the cost control and reduced design iterations and testing with physical prototypes, we deliver highquality sheet metal parts.
When you select kfactor as the bend allowance, you can specify a kfactor bend table. In sheet metal, there is a powerful bend constant known as the k factor. Bend deduction explained with formula and calculator. Kfactor is a ratio that represents the location of the neutral line with respect to the thickness of the sheet metal. Please note the bending of sample part is done in the same manner as we are planning for production. So for a very large radius bend where the neutral axis lies right in the center of the material, the kfactor would be exactly 0. Bending is a manufacturing process that produces a vshape, ushape, or channel shape. Sheet metal is an external workbench evolved to design and unfold sheet metal parts. And if you know the bend allowance, you can extract the kfactor from it. The k factor is defined as the ratio between the material thickness t and the neutral fibre axis t, i. In this article we will discuss sheetmetal bend deduction, bend allowance, k factor, y factor and sheet metal flat pattern calculations. Best way to calculate k factor in sheet metal is by reverse engineering. Analyzing the kfactor in sheet metal bending the fabricator.
The kfactor is nothing more than a multiplier that can give you an accurate value for the relocated neutral axis. It ultimately allows you to estimate the amount of stretch without knowing what type of material you are bending. We produce a lot of sheet metal work using invento and use 0. Kfactors, yfactors, and press brake bending precision. Since the inside compression can not exceed the outside tension, the kfactor can never exceed. When a piece of metal is being formed, the inner portion of the bend compresses while the outer portion expands see figure 1. This can lead to a lot of confusion and errors when designing and calculating flat patterns. Just like ba and kfactor, sheet metal bend deduction is also a very crucial part of sheet metal design terminology. What are bend allowance, bend deduction and kfactor. We are just starting on this project so we use the same diesbend radii for all parts. Sheet metal k factor what is it and how to measure it solidworks duration. Well, when a sheet is bent in the press brake, the part of the sheet close to and in contact with the punch elongate to compensate for the given bend if you compare the length of this part, before and after the bending, youre going to find that theyre different.
So for a very large radius bend where the neutral axis lies right in the center of the material, the k factor would be exactly 0. Hybrid design we can now create wireframe and surface features within the same. Using a variety of y and k factor bend allowance calculations, designers can create flat patterns of the designs. Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport, ohio 43125 duct system design i notice. Therefore it is important to have the value correct in cad software. At form2000, we have a sheet metal engineering suite in our factory in melbourne, and we are equipped with 3d design and simulation software, which enables our team of expert engineers to reach the optimal machine selection and order of operations required to efficiently manufacture your sheet metal product. The k factor can be customized by excel spreadsheets and the bend radius can be set after the part has thickness by editing the sheet metal feature in the browser bar. As explained in bend allowance, when sheet metal is bent, the inside surface of the bend is compressed and the outer surface is stretched, but somewhere within the thickness of the metal lies its neutral axis, which is a line in. In the improved design, the sheet metal only needs one bending process to complete the bending of the two sides at the same time. A sheet formed part is usually obtained through a number of operation phases final surface intermediate. Pdf the study of design constants in sheet metal forming.
Me is a community and comprehensive knowledge base for the engineering design and fabrication of sheet metal. Demonstrate to employers that you understand the set of solidworks tools that aid in the design of sheet metal components by completing the certified solidworks professional advanced sheet metal cswpasm exam. It is used to calculate bend allowance and bend deduction which are further used to calculate the flat pattern. The sheet metal model built with the sheet metal addon rear. Bend the sheet to 90 degrees and measure length a and b. Sheet metal unfold rule equations ketiv technologies. First of all, let me explain why and where you need to use this bend deduction.
Avoid large sheet metal parts with small bent flanges. This comprehensive suite of creo sheet metal design tools helps users create features such as walls, bends, punches, notches, forms, and relief features. Sheet metal addon for freecad open source cad software. In sheet metal, the kfactor is the ratio of the neutral axis to the material thickness. If you noticed there is no library of material for the k factor and you were not prompted for the bend radius. Calculating bend allowance, bend deduction, and kfactor. When making bends, it takes material specifications into account. The k factor is the most important and elusive variable of bending, because it varies both as a function of the material and according to parameters such as angle and tooling. Our sheet metal design will use the following specifications. Once you know the kfactor, you can use it to predict the bend allowance for various angles. In sheet metal design, the kfactor is used to calculate how much sheet metal one needs to leave.
Sheet metal is used in the production of materials ranging from tools, to hinges, automobiles etc. As there is no special support for it in freecad, it tends to take time to design sheet metal parts, as i need to manually add sketches, extrude walls, and add fillets. You can specify an explicit bend allowance or bend deduction for any sheet metal bend by entering the value when. It is used to calculate sheet metal flat length flatpattern. Bending calculations using kfactor, bend deduction, and bend allowance. In my previous post i talked about kfactor, bend allowance and bend deduction and what they mean in sheet metal design. Below are some tips and guidelines for designing sheetmetal parts. Relationship between bend deduction, bend allowance, and k factor. Calculate k factor, bend allowance and y factor for sheet. You can use this kfactor calculator to calculate k factor using reverse engineering method. Kfactors are a great tool for developing flat blanks for sheet. Calculate k factor, bend allowance and y factor for sheet metal bending. Steel kfactor pressbrake forming solidworks forums.
296 444 1544 338 1322 95 1186 1096 297 1342 441 899 49 1039 1364 943 1006 72 505 1402 512 1450 902 432 228 334 1093 1401 591 365 1541 1534 616 1033 1094 1392 343 138 176 1454 34 1045 1266