As far as solidworks goes, it seems i apply one kfactor for all sheet metal pieces when i convert a body into sheet metal. Determining the kfactor for sheet metal cr4 discussion thread. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. Best way to calculate k factor in sheet metal is by reverse engineering. There is little overhead used by this monitoring process it will be unnoticeable. Charts of theoretical stressconcentration factors k. The k factor is defined as the ratio between the material thickness t and the neutral fibre axis t, i. Sheet metal unfold rule equations ketiv technologies.
Apr 25, 2018 kfactor a constant determined by dividing the thickness of the sheet by the location of the neutral axis, which is the part of sheet metal that does not change length. Therefore if a kfactor addin is running the sheet metal kfactor will update automatically whenever the thickness or bend radius is changed. The bend allowancebend deduction of the sheet metal specified in k factor by configuring and utilizing a sheet metal gauge table, we can speed up the process of selecting the correct wall thickness based on gauge value and selecting. Jun 06, 2017 figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. When you select k factor as the bend allowance, you can specify a k factor bend table. In this article we will discuss sheetmetal bend deduction, bend allowance, kfactor, yfactor and sheet metal flat pattern calculations. 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. The sheet metal model built with the sheet metal addon rear.
Ms2011060 rev 0 22 nd february 2011 guide by clinton brown kfactor in autodesk inventor sheet metal parts the k factor in sheet metal is the ratio of thickness to the location of the. When metal is bent the top section is going to undergo compression and. The inside radii are based off of a standard air bend force chart. Kfactor a constant determined by dividing the thickness of the sheet by the location of the neutral axis, which is the part of sheet metal that does not change length. In this article we will discuss sheetmetal bend deduction, bend allowance, k factor, y factor and sheet metal flat pattern calculations. Powder coating is a commonly used surface finishing technique. I had a question on kfactors for our 3d modeling software. Determining the kfactor for sheet metal 12052008 9. I had a question on k factors for our 3d modeling software. The kfactor is the ratio of the neutral axis location t. Approximate stressconcentration factor kt for bending of a round bar or tube with a transverse round hole source. Describing that shift is what the kfactor is all about.
Nov 30, 2018 learn what a k factor is in sheet metal forming, learn how k factor is used, and learn how to calculate k factor in this video. From there we can calculate the k factor and the bend deduction. Cut a sample sheet and measure its total flat length and sheet thickness in mm. In over 50 years of serving the mechanical system marketplace, mcgill airflow has gained a technical expertise, which is unmatched in the industry. After bending the sheet we need to do some measurements as shown in figure 2. And, you have all the dimensions of the final component in your design. The main reason that i compared it ti the appearance ui is that it clearly has a standard library, you custom items, and also shows what is. The kfactors at the lhc are similar to the kfactors for thesame processes at the tevatron, but have a tendency to be smaller.
K factor 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. Value of k factor depends on material, sheet thickness, inside bend radius and machine used. Sep 28, 2015 kfactor a constant determined by dividing the thickness of the sheet by the location of the neutral axis, which is the part of sheet metal that does not change length. Solidworks in your industry pt7 sheet metal duration. Relationship between bend deduction, bend allowance, and k factor.
Jun 25, 2019 mathematically k factor is equal to position of neutral axis divided by sheet thickness. You can easily modify the material thickness, inside radius and kfactor for each thickness at the top of each column. It is used to calculate sheet metal flat length flatpattern. 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. Kfactor calculator for sheet metal bending smlease design. Dec 27, 2016 when working in solidworks to create sheet metal designs, we will often need to know three important values.
This change in sheet length depends on the position of neutral axis or k factor. Best way to calculate k factor is to do a simple experiment by cu. Pdf the study of design constants in sheet metal forming. Not sure where this shows up other than in this table. The value of the kfactor should range between 0 0,5. When metal is bent the top section is going to undergo compression. Sep 10, 2014 sheet metal k factor what is it and how to measure it solidworks duration. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. First of all, let me explain why and where you need to use this bend deduction. Input material thickness and and inner radius to get the data of k factor, y factor, neutral layer.
The difference between k factor, bend allowance and. Determining the k factor for sheet metal 12052008 9. 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. Mar 07, 2018 when you bend sheet metal, the neutral axis shifts toward the inside surface of the bend. Setbacks, bend allowances and k factors are somewhat. 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. The solidworks application also comes with a k factor bend table in microsoft excel format. Kfactor is a ratio that represents the location of the neutral line with respect to the thickness of the sheet metal. K factors are a great tool for developing flat blanks for sheet. Suppose that you have designed a sheet metal component for fabrication. While modern bend deduction charts now are reasonably accurate, historically bend calculation charts, both for bend allowances and bend deductions, were notorious. Learn sheet metal design terminology including bend deduction.
Peterson, stressconcentration factors, wiley, new york, 1974, pp. Y factor and k factor represent part constants used in formulas to calculate the developed length of flat sheet metal required to make a bend of a specific radius. Calculating bend allowance, bend deduction, and kfactor. In sheet metal design, the k factor is used to calculate how much sheet metal one needs to leave for the bend in order to achieve particular final dimensions. If you noticed there is no library of material for the k factor and you were not prompted for the bend radius. The thinning sheet forces the neutral axis to shift inward toward the inside bend radius. The yfactor is used, as far as i know, solely by ptcs proengineer, now known as creo elementspro.
When you bend sheet metal, the neutral axis shifts toward the inside surface of the bend. The kfactor is primarily dependent upon the material stiffness. The kfactors tend to be closer to unity if either the same nlo pdf is used for both the lo and nlo calculations, or equivalently, if the cteq modi. The kfactor is the ratio of the neutral axis location t to the material thickness mt. It allows you to anticipate the bend deduction for a large variety of angles without having to rely on a chart. In inventor this ratio determines the final size of the unfolded sheet metal part. K factor is a ratio that represents the location of the neutral sheet with respect to the thickness of the sheet metal part. The information on the web site above helped me greatly achieve a somewhat accurate kfactor until i was finally given our companies k. Calculate k factor, bend allowance and y factor for sheet metal bending. This publication shares a part of that expertise with the engineers, designers. Since the inside compression can not exceed the outside tension, the k factor can never exceed.
Therefore, it is not part of the standard freecad install. The k factor is the ratio of the neutral axis location t to the material thickness mt. Kfactors, yfactors, and press brake bending precision. In fact, sheet metal use in hvac is greater than all other materials combined. Mathematically k factor is equal to position of neutral axis divided by sheet thickness. To a lesser extent, it is effected by the bend radius. Kfactor sheet metal, the ratio of location of the neutral line to the material thickness. A great majority of metallic ducts is made of galvanized steel. Bend deduction explained with formula and calculator. The kfactor is used to calculate flat patterns because it is related to how much material is stretched during bending.
We can calculate the leg length 1 and 2 as follows. How to use this k factor calculator in sheet metal reverse engineering approach step1. The main reason that i compared it ti the appearance ui is that it clearly has a standard library, you custom items, and also shows what is unique to the document. Shows up in the property manger of the sheet metal feature in the bend allowance group box as bold text left of gauge table values. The k factor in sheet metal is the ratio of thickness to the location of the neutral line in the metal cross section. Autodesk inventor kfactor sheet metal cadline community. The k factor in sheet metal working is the ratio of the neutral axis to the material thickness. The information on the web site above helped me greatly achieve a somewhat accurate k factor until i was finally given our companies k factor chart that we go by. Press brake bend allowance chart free technical charts. Fabrication calculator for kfactor, yfactor, bend allowance. Kfactor is a ratio that represents the location of the neutral axis with respect to the thickness of the sheet metal part and depends on material, thickness and bend radius. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness.
With this free online tool you can calculate the k factor, a fundamental parameter used to calculate sheet metal elongation according to your bending setting. So if the thickness of the sheet was a distance of t 1 mm and the location of the neutral axis was a distance of t 0. Bending a known length of sheet metal is easy, but to calculate the bend. Sheet metal is an external workbench evolved to design and unfold sheet metal parts. Learn what a kfactor is in sheet metal forming, learn how kfactor is used, and learn how to calculate kfactor in this video. When working in solidworks to create sheet metal designs, we will often need to know three important values. Sheet metal k factor what is it and how to measure it solidworks duration. Calculate k factor, bend allowance and y factor for sheet. Shows up in the property manger of the sheet metal feature in the sheet metal gauges group box, under the table name.
Apr 30, 2011 download k factor lessthan90degreebends. How to set up sheet metal gauge tables engineers rule. Jul 24, 2017 it really all depends on what tooling is used to produce the sheet metal part and of course what material is being used. The k factor depends on many factors including the material, the type of bending operation coining, bottoming, airbending, etc. It really all depends on what tooling is used to produce the sheet metal part and of course what material is being used. Blank development for formed sheet metal parts there are many systems employed by a variety of industries aircraft, electronics, architectural, automotive, etc. It is a type of coating that is applied as a freeflowing, dry powder. The kfactor in sheet metal working is the ratio of the neutral axis to the material thickness. The steel and aluminum used for ductwork is a high achiever in the 21stcentury move toward sustainable buildings because of the high recycling rates and cleanliness. The kfactor is fundamental to designing precise sheet metal products. In most cases the bend radius would be the same for multiple bends and therefore the kfactor is the same. Determining the kfactor for sheet metal cr4 discussion. Please note the bending of sample part is done in the same manner as we are planning for production.
Sheet metal bending design tips, bend allowance, k factor, etc. Analyzing the kfactor in sheet metal bending the fabricator. Now, you may be thinking, where this k factor is used. Then input the bend angle to get the arc length, bend allowance and bend deduction.
What are all the surface finish processes used for sheet metal fabrication. Therefore it is important to have the value correct in cad software. The line where the transition from compression to stretching occurs is called the neutral axis. Sheet metal k factor user modification i also thought about referencing the parameters ui, which would work well also. Kfactor is a ratio that represents the location of the neutral sheet with respect to the thickness of the sheet metal part. When you select kfactor as the bend allowance, you can specify a kfactor bend table. Our solidworks experts can setup your environment so that your team uses a comprehensive set of. Let me make it clear that it is a very important term used in sheet metal design. Calculate k factor, bend allowance and y factor for sheet metal. Then input leg length a and b to get the flat size of the sheet. When sheet metal is bend, the inside bending surface is compressed. The bend allowancebend deduction of the sheet metal specified in kfactor by configuring and utilizing a sheet metal gauge table, we can speed up the process of selecting the correct wall thickness based on gauge value and selecting.