Are you trying to use stainless steel sheets as the material in your project? If so, you might want to think about using the correct sheet metal bend radius. This article will discuss how to calculate the radius, design a bend, and notch your piece to get it just right. This will keep your bend radius consistent and avoid unnecessary tooling costs. We hope these tips will make your work more accurate and efficient.

5 Things To Consider When Using The Proper Sheet Metal Bend Radius For Your Projects | TBK Metal

Things To Consider When Using The Proper Sheet Metal Bend Radius


When you're looking to make a custom bend in sheet metal, you'll want to take into account the outside bend radius and the minimum flange length. When calculating the outside bend radius, remember that the flange length should be about six times as wide as the material's thickness, and the bend radius itself should be about two-thirds of the material's thickness. In general, the greater the bend radius, the more accurate your bend will be.

When it comes to the outside bend radius, the more bumps you use, the smoother the outside bend radius will be. When using a circular bend, you'll need to make sure to bump the metal only 2 degrees for each hit. This will ensure a smooth 90-degree bump bend and prevent the bend from distorting the metal itself. When you're calculating the outside bend radius, the less bumps you make, the more accurate your band will be.


To design a bend on a piece of sheet metal, you should consider the thickness of the material. Ideally, the inner radius of a bend should be the same as the thickness of the material. If you set the inner radius too high, you might end up with a hole that is larger than the sheet metal thickness. A smaller inner radius will help you with calculations, but a large one will cause problems.

When you design a bend, the inside radius will vary from batch to batch and shop to shop. It's not uncommon to adjust the bend radius on a flat blank to match the desired radius. Sheet metal, like other metals, has memory. This means that the bend radius will have to be overbent to achieve the desired angle. Designers of sheet metal parts should care about the flat layout, as this is the prediction of what the finished part will look like before it is bent. Fabricators, however, may alter the flat layout for immediate circumstances.


To make sheet metal parts with a tight bend radius, slot them at the bending axis. You can slot as little as one-fourth of an inch of steel. A good rule of thumb is to set the bridge width at 1/4th of the material thickness, which is about 3/4 of the material thickness T. However, you must not exceed the inner radius, which should not be larger than two-thirds of the material thickness.

The right tool for the job is essential in ensuring that you get the correct result. To ensure that you get a high-quality bend, choose the correct tool to handle the material. If the material is too thin, use a larger tool, such as a bending lathe, or a sheet metal jigsaw. The correct tool can even allow you to measure the bend radius.

Keeping A Consistent Bend Radius

Keeping a consistent bend radius is a critical factor in the design of precise sheet metal products. This metric helps designers predict bend deductions. Modern bend calculation charts are fairly accurate, but they were notoriously inaccurate when first developed. Even then, they were often valid for a specific manufacturing environment. That's why it's so important to calculate the bend allowance carefully, and to use these curves when calculating your flat layout.

When designing bends, always keep the inside radius equal to the thickness of the sheet metal. A consistent bend radius will also help you minimize the risk of torn metal. Designed bends must follow the same plane and direction, so the bend radius needs to be consistent throughout the entire part. This helps keep parts affordable and prevent torn metal. Using a standard die set with 0.80-mm internal corner tools is a great way to ensure that you'll get the bends you need.

Using Air Bending

If you need to bend sheet metal, you might want to use air bending as a method. It's a common sheet metal fabrication method that produces accurate bends. The process is similar to coining, but differs slightly. Instead of pressing the metal plate into the die, the top tool forces it into the bottom die. Coining has little spring back and can achieve an inside radius of only 0.4 T. While this method produces high precision, it's also expensive and requires special tools.

One of the biggest challenges of air bending is the variations in the material thickness. Material thicknesses vary throughout a batch. The process of sizing a sheet at a rolling mill can also cause variations in thickness. Anisotropy is the property that makes material react differently to different directions. This process can result in different bend lengths, and sheet metal fabrication professionals should account for this factor when planning their projects.

The Benefits Of Using Bent Sheet Metal

The benefits of bent sheet metal include cost-effectiveness, durability, and springback. Let’s discuss some of the most important advantages. Bended sheet metal is a better option than bent steel, aluminum, or copper. Read on for more information. Here are a few of them:


One way to reduce the cost of manufacturing parts using bent sheet metal is to design them with simple angled bends. These are less costly than more complex shapes and avoid unnecessary reorientations. Ideally, the bend radius should be the same as the thickness of the sheet metal. The more complex the part is, the more expensive it will be. However, the more basic the part, the more cost-effective it will be.

Generally speaking, the cost-effectiveness of using bent sheet metal increases with the volume of parts. For example, CNC bending requires the production of each bend separately, which means that the time required to produce each component increases. However, progressive stamping and CNC bending can increase throughput and automation, thereby reducing costs. By contrast, bent sheet metal can be produced quickly and with a low investment.


The bendability of a sheet metal varies widely, depending on several factors including the material, thickness, radius of the bend, and the method of forming it. In addition, the bendability of a metal varies with its thickness and the mechanics of its manufacture, such as the angle of the bend and tooling used. However, the bendability of a metal largely depends on its metallurgy and form.

During a bending operation, the material undergoes residual stresses called springback. In some cases, elastic recovery is possible, making the bend radius smaller. Springback is the difference between the final bend angle and the initial bend angle. The amount of springback varies depending on the material, bending process, initial bend angle, and springback factor. Hence, springback is a critical consideration in any sheet metal bending process.


CNC bending is one of the underrated processes for low to medium-volume sheet metal production. This process can produce a wide variety of part geometries without the need for tooling, improving the quality of your parts while reducing your cost. This process also has fast lead times and high levels of repeatability. This process also requires little to no tooling investment, allowing for quick turn-around times. Whether you are looking to make a single part or are planning to produce multiple parts, CNC bending is the way to go.

The K-factor value of a material is a number that provides information to determine the bend allowance. The K-factor is the ratio of the material's neutral axis to its thickness. If you know the K-factor of the material, you can determine the thickness of the metal. Then, multiply the thickness by the K-factor. Once you know the K-factor, you can accurately calculate the cost of using bent sheet metal.


This study examines the springback of mild steel during V-bending. The effects of sheet thickness, bending angle, and tool radius were investigated. The results of this study show that the use of bent sheet metal improves structural panel formability. The researchers also considered the impact of punch radius in influencing springback. The researchers concluded that springback can increase structural panel performance by up to 30%. Springback can also be a good choice for forming lightweight structures, since it reduces the risk of buckling or distortion.

Bending is a common industrial process. The use of bent sheet metal provides many benefits, including strength, ductility, and aesthetic appeal. While springback is a variable factor, it can be forecasted, making it easier to select tooling for certain jobs. When used properly, bent sheet metal can have a 50-degree springback or more, especially in high-strength steels. Springback depends greatly on the yield strength of the material. The higher the yield strength, the greater the amount of springback. The inside radius of the bend is greater than the outer radius, and this increases springback.

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