File Name: k factor and y factor .zip
- Sheet Metal Bending – Methods, Design Tips & K Factor
- Sheet Metal Bending – Methods, Design Tips & K Factor
- SOLIDWORKS Design & Help
Only problem I am running into is what bend radii and what k-factors do I input to Solidworks to ensure that my flat views of each component are correct when i create the prints. If anyone has worked with SS and the sheet metal bending features on solidworks and knows what these values should be You'd save me a lot of material and time bending samples and doing calculations.
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. The K factor is defined as the ratio between the material thickness T and the neutral fibre axis t , i. Bend allowance is a fundamental parameter to calculate sheet elongation. This is defined as the length of the neutral fibre from the beginning to the end of the arc generated by the bend. To calculate the bend allowance, the K factor and the derived coefficient called the Y factor, insert the thickness and initial length of the sheet into the cells on the left.
Sheet Metal Bending – Methods, Design Tips & K Factor
Stop wasting time on admin! Order your sheet metal fabrication online. Immediate pricing and short lead times all over the UK. Bending is one of the most common sheet metal fabrication operations. Also known as press braking, flanging, die bending, folding and edging , this method is used to deform a material to an angular shape. This is done through the application of force on a workpiece.
Only then can you get a lasting result in the form of a bend. What are the most common bending methods? How does springback affect bending? What is k factor? How to calculate bend allowance? We have also written another important post about press brake tooling.
Knowing the tools helps you to engineer products that can be manufactured. Each has their own advantages. The dilemma is usually between going for accuracy or simplicity, while the latter gets more usage.
Simpler methods are more flexible and most importantly, need less different tools for getting a result. V-bending is the most common bending method using a punch and die. It has three subgroups — bottoming, air bending and coining. Each operation needs a certain tonnage per meter. This is also shown in the table. You can see that thicker materials and smaller inside radii require more force, or tonnage.
The highlighted options are recommended specifications for metal bending. To keep it simple, I also use a 2 mm inside radius. I can now see that the minimum flange length is 8. The required die width is 12 mm and tonnage per meter is The lowest common bench capacity is around tonnes. Therefore, even a simple bench with enough room to bend 3 m pieces will do the job. Still, there is one thing to keep in mind. This table applies to construction steels with a yield strength around MPa.
When you want to bend aluminium , the tonnage value can be divided by 2, as it needs less force. The opposite happens with stainless steel — the required force is 1.
Bottoming is also known as bottom pressing or bottom striking. As the inner line gets compressed, it needs more and more force to further manipulate it. Bottoming makes exerting this force possible, as the final angle is preset. The possibility to use more force lessens the springback effect and provides good precision. Partial bending, or air bending, derives its name from the fact that the working piece does not actually touch the tooling parts entirely. In partial bending, the workpiece rests on 2 points and the punch pushes the bend.
Is still usually done with a press brake but there is no actual need for a sided die. Air bending gives much flexibility. With this method, you can get a result anywhere between 90 and degrees. Though less accurate than bottoming or coining, this kind of simplicity is the beauty of the method.
Of course, this is a result of lessened accuracy compared to bottoming. Coining used to be far more widely spread. It was pretty much the only way to get accurate results.
Today, machinery is so well controllable and precise, that such methods are not widely used any more. Coining derives it name from coins, as they have to be identical to make fake money distinguishable from the real one.
Coining, in bending, gives similarly precise results. For instance, if you want to get a 45 degree angle, you need a punch and a die with the exact same angle. There is no springback to worry about. Because the die penetrates into the sheet, pressing a dent into the workpiece. This, along with the high forces used about times as much as in partial bending , guarantee high precision. The penetrating effect also ensures a very small inside radius for the bend.
U-bending is in principle very similar to V-bending. There is a die and a punch, this time they are both U-shaped, resulting in a similar bend. This is a very straightforward way for bending steel U-channels, for example, but not so common as such profiles can also be produced using other more flexible methods.
Step bending is, in essence, repetitive V-bending. Also called bump bending, this method uses many V-bends in succession to get a large radius for your workpiece. The final quality depends on the number of bends and the step between them. The more you have them, the smoother the outcome.
Bump bending is used in many cases. Some examples include conical hoppers and snowploughs. It makes large radius bending possible with regular tools.
The easier setup makes for a cheaper price, especially with small batches. Roll bending is used for making tubes or cones in different shapes. Can also be used for making large radius bends, if needed. In the process, there are two driving rolls and a third adjustable one.
This one moves along via frictional forces. If the part needs to be bent at both ends as well as the mid-section, an extra operation is required. This is done on a hydraulical press or press brake. Otherwise, the edges of the detail will end up flat. Wipe bending, or edge bending, is another way to bend sheet metal edges. It is important to make sure that the sheet is properly pushed onto the wipe die.
The slack between the wipe die and the punch plays an important role in getting a good result. Another way to bend edges is through rotary bending. Actually, there are special polymer tools available to avoid any kind of tool marking, let alone scratches. Rotary benders can also bend sharper corners than 90 degrees. This helps greatly with such common angles, as springback is not a problem any more.
The most common method is with 2 rolls but there are also options with one roll. This method is also suitable for producing U-channels with flanges that are close by, as it is more flexible than other methods. If you would also like to read about steel tube bending methods , we have it covered along with tube bending machinery. When bending a workpiece, it will naturally spring back a little after the load is lifted. Therefore, it has to be compensated for when bending.
The workpiece is bent beyond the required angle, so it takes the wanted shape after springback. The larger the inside radius, the bigger the springback effect. A sharp punch gives a small radius and relieves the springback. Why does springback occur? When bending parts, the bend is divided into two layers with a line separating them — the neutral line. On each side, a different physical process is taking place.
Each type of metal has different values for the loads they can take when compressed or pulled. And the compressive strength of a material is far superior than the tensile strength. As a result, it is more difficult to reach permanent deformation on the inner side. This means that the compressed layer will not get deformed permanently and tries to regain its former shape after lifting the load. If you design your bent sheet metal parts in CAD software that has a special sheet metal environment, use it.
It exists for a reason. When making bends, it takes material specifications into account. All this information is necessary when making a flat pattern for laser cutting.
Unless you use our manufacturing service where CAD models are accepted for production , you need to keep producing those flat pattern drawings. Bending elongates the material. This means that the neutral line or axis, as we talked in the springback section, is not really in the middle of the material.
Sheet Metal Bending – Methods, Design Tips & K Factor
Mathematically k factor value is equal to the ratio of position of 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? Sheet metal bending is a forming operation where sheets are deformed plastically to change its shape. During sheetmetal bending, 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 bend allowance and bend deduction is calculated using a constant known as K factor or Y factor.
Bending is a manufacturing process that produces a V-shape, U-shape, or channel shape along a straight axis in ductile materials, most commonly sheet metal. Typical products that are made like this are boxes such as electrical enclosures and rectangular ductwork. In press brake forming, a work piece is positioned over the die block and the die block presses the sheet to form a shape. When bending is done, the residual stresses cause the material to spring back towards its original position, so the sheet must be over-bent to achieve the proper bend angle. The amount of spring back is dependent on the material, and the type of forming. When sheet metal is bent, it stretches in length.
In sheet metal, there is a powerful bend constant known as the K-Factor. It ultimately allows you to estimate the amount of stretch without knowing what type of material you are bending. Here is a book definition of K-factor:. K-Factor — 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. Once you activate the base flange tool, you have an available list of parameters you need to specify to determine how sheet metal is going to stretch. We can now apply the Bend Allowance Formula using the above information. The Bend Allowance Formula will determine the length of the arc at the neutral axis from one bend line to the other.
Keywords: sheet metal forming, K factor, bend allowance Bending in a V-die is a widely used process where the part is initially air bend until.
SOLIDWORKS Design & Help
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Figure 1 When you bend sheet metal, the neutral axis shifts toward the inside surface of the bend. The K-factor is the ratio of the neutral axis location t to the material thickness Mt. Question: I had a question on K-factors for our 3-D modeling software.
The K-Factor in sheet metal working is the ratio of the neutral axis to the material thickness. The line where the transition from compression to stretching occurs is called the neutral axis. Below the image shows how the top of the bend is compressed, and the bottom is stretched. The K-Factor is used to calculate flat patterns because it is directly related to how much material is stretched during the bend.
Ее черный лоснящийся верх поднимался на двадцать три фута, а сама она уходила далеко вниз, под пол. Своей гладкой окружной формой она напоминала дельфина-косатку, застывшего от холода в схваченном морозом море.
Он посмотрел на приближающуюся фигуру, затем перевел взгляд на кольцо. Из-за чего погибла Меган. Неужели ему предстояло погибнуть по той же причине. Человек неумолимо приближался по крутой дорожке. Вокруг Беккера не было ничего, кроме стен. По сторонам, правда, находились железные ворота, но звать на помощь уже поздно.
Если нужно, используйте против всех нас слезоточивый газ. Если мистер Хейл не образумится, снайперы должны быть готовы стрелять на поражение. Всю ответственность я беру на. Быстрее. Хейл выслушал все это, не сдвинувшись с места и не веря своим ушам. Хватка на горле Сьюзан слегка ослабла. Стратмор выключил телефон и сунул его за пояс.
Он стремительно развернулся и едва сдержал крик. Никого. Дэвид Беккер исчез. Тремя пролетами ниже Дэвид Беккер висел на вытянутых руках над Апельсиновым садом с наружной стороны Гиральды, словно упражняясь в подтягивании на оконном выступе. Когда Халохот поднимался по лестнице, Беккер, спустившись на три пролета, вылез через один из проемов и повис на руках. Сделал он это как раз вовремя - убийца промчался мимо в ту же секунду. Он так торопился, что не заметил побелевших костяшек пальцев, вцепившихся в оконный выступ.
Он снова ответил Да. Мгновение спустя компьютер подал звуковой сигнал. СЛЕДОПЫТ ОТОЗВАН Хейл улыбнулся.
В нем не было ни картин, ни мягкой мебели, ни фикусов в горшках, ни антикварных часов. Здесь все было подчинено одному требованию - эффективности. Стол, накрытый стеклом, и черный кожаный стул были расположены прямо перед громадным венецианским окном. Три шкафа-картотеки стояли в углу рядом с маленьким столиком с французской кофеваркой.
Внезапно он почувствовал страх, которого никогда не испытывал. Беккер наклонил голову и открыл дроссель до конца. Веспа шла с предельной скоростью. Прикинув, что такси развивает миль восемьдесят - чуть ли не вдвое больше его скорости, - он сосредоточил все внимание на трех ангарах впереди. Средний.
Правда, оставалась еще одна проблема - Дэвид до сих пор не нашел второй экземпляр ключа. Она молилась, чтобы его усилия увенчались успехом. Направляясь к центру Третьего узла, Сьюзан пыталась привести свои мысли в порядок. Странно, что она чувствует нервозность в такой знакомой ей обстановке. В темноте все в Третьем узле казалось чужим.
Сзади, перпендикулярно туннелю, начинался коридор, едва освещаемый красными лампочками, вмонтированными в пол. - Пойдемте, - позвал Бринкерхофф, помогая Сьюзан вылезти.