How to bend a stainless steel panel?

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Summary

1 What Is The Stainless Steel Sheet Bending?

2 Features Of Stainless Steel Sheet

   2.1 Thickness

   2.2 Material

   2.3 Surface

3 Bending Way Of Stainless Steel Sheet

   3.1 Bend by hand

   3.2 Bend metal cold

   3.3 Bend metal hot

4 Stainless Steel Sheet Bending Factors

   4.1 Bending angle

4.2 Bending radius

4.3 Bending rebound

4.4 Bending allowance

4.5 Other factors

5 What Is The Sheet Metal Bending?

6 Types Of Sheet Metal Bending Techniques

7 Sheet Metal Bending Experience

8 Conclusion

What Is The Stainless Steel Sheet Bending?

Stainless steel sheet bending is the process of the sheet to forming the specific shapes;

Stainless steel sheet bending is widely used in sheet metal working, and it is also an essential stage in metal fabrication;

Stainless steel sheet bending provides forming processing, customized processing, and mass production for stainless steel works.

Features Of Stainless Steel Sheet

Stainless steel sheets refers to a type of alloy steel that is resistant to weak medium corrosion such as atmosphere, steam, and water. It is not easy to rust, but it does not mean that it will never rust. And It was become important metal materials due to their excellent corrosion resistance.

Thickness

According to the thickness, It can be divided into sheet (0.2mm-4mm), medium plate (4mm-20mm), heavy plate (20mm-60mm).

Materials

Stainless steel sheet mainly has the following four different grade:

• Austenitic stainless steel

• Ferrite stainless steel

• Martensitic stainless steel

• Duplex stainless steel

In stainless steel sheet metal processing, most use 201,202,301,303,304,304 L, 316 and other grades, they all belong to austenitic stainless steel.

Surface

According to different surface condition, stainless steel sheets have the distinguish and applications:

-NO1, silver white without luster

-NO2D, silver white

-NO2B, with better gloss than NO.2D, generally made of materials

-BA, glossy, building material, used for kitchen equipment

-NO3, coarse grinding, building materials, kitchen equipment

-NO4, intermediate grinding

-NO240, finely ground

-NO320, very fine grinding

-NO400

-HL, building materials

-NO7, for art use and decoration

-NO8, mirror grinding, reflector, decorative

Bending Way Of Stainless Steel Sheet

Bend by hand

In the absence of professional equipment, we need to find some other auxiliary tools, such as marking pens, angle rulers, rulers, flat pliers, and hammers. Please note that this method is only suitable for thin sheet bending.

Firstly, calculate the bending allowance, mark the bending line with a ruler and marking pen, and then cut the size of the sheet. Clamp the sheet tightly with a flat jaw pliers, and use a hammer or manual bending to the size. Use an angle ruler to check and repeat the operation until the bending is completed

Bend by Hot

When the thickness of the stainless steel sheet is thickened, we need to heat the sheet and perform hot bending. Put the sheet metal into the hot press machine, the machine will heat the sheet metal with high frequency, and shape it by hot pressing with the mold. This method requires customized molds for mass production, and is mostly used for wood plate and acrylic plate bending processing.

Bend by Cold

In the cold bending, Hydraulic Press brake and hydraulic rolling machine are usually needed.

The hydraulic Press brake can use the upper punch to apply downward pressure to bend the stainless steel sheet surface to the specified angle. During bending, the ratio of the sheet thickness to the notch of the lower die of the Press brake also needs to be considered. 

Generally, choose die channel (V) = thickness (T) × 8.

In addition, when you have special requirements for the bending surface, such as reducing sheet strain, you can choose:

Adjustable die

Rolla-V die

It can achieve traceless bending of the sheet metal

When bending a hydraulic rolling machine, it is also necessary to shape the metal sheet into circular, elliptical, and conical shapes based on the thickness and tensile strength of the material.

Stainless Steel Sheet Bending Factors

According to the characteristics of stainless steel sheet, the thicker the thickness of the plate per unit size, the greater the bending force required, so the bending force of the press brake should be considered in advance.

Related links:
How much does a Salvagnini panel bender cost?

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Bending angle

Stainless steel sheet have high tensile strength, low elongation, high bending force required, and large bending angle.

Bending radius

The larger the bending radius, the rebound will also increase, so when bending stainless steel sheet, the bending radius and bending angle should not be too small, otherwise bending cracks will occur.

Bending rebound

Due to the higher yield strength of stainless steel compared to carbon steel, the elastic recovery is greater. There may be inconsistencies in the bending angle, bending radius, and mold size. Therefore, using a sharper Upper punch produces a smaller bending radius and reduces sheet rebound.

Calculate bending allowance

Because bending elongates the sheet, it means that the intermediate line may not be truly located in the middle of the sheet. At this point, we need to calculate the bending allowance. Firstly, we need to calculate the K-factor, which is influenced by material, thickness, bending radius, and bending method. By using the K-factor, you can obtain bending allowance.

The K factor can be selected based on the following datasheet and different materials, which can provide you with sufficiently accurate results:

Secondly, calculate the bending allowance using the formula.

0° ≤  β ≤ 90°

90° ＜ β ≤ 165°

β = bending angle （°）

When the Angle exceeds 165°, there is no need to calculate the bending allowance.

Other factors

(1) Does the X-axis direction exceed the maximum limit of the Back language;

(2) Whether the length of the sheet exceeds the maximum machine bending length;

(3) Whether the Press brake die will send collision during U-bending;

(4) Whether the two sides of the box collide when folding the deep box;

(5) Will the protruding part of the bending line be pressed.

What Is The Sheet Metal Bending?

Sheet metal bending includes various materials, such as mild steel sheet, Carbon steel sheet, Stainless steel sheet, Aluminum sheet, etc. Therefore, this industry is widely present and applied in multiple fields.

Types Of Sheet Metal Bending Techniques

V bending

V-bending is a common bending method using Upper punch and Lower die; It can be divided into bottoming, coaching, and Air bending and bottoming account for 90% of all bending work.

  Bottoming

The Upper punch completely presses the metal sheet into the Lower die, so the angle of the mold determines the final angle of the workpiece. Bottoming can reduce sheet rebound and provide good accuracy.

  Air bending

Air bending provides greater flexibility, helping you achieve results between 90 and 180 degrees with multiple bends as adjustments. Of course, its accuracy will be lower than Bottoming.

   Coining

Coining has been popular in the past, but with the development of CNC Press Brake, its use has gradually decreased.

U bending

U bending is similar to V bending in that it also uses the Upper punch to press down on the Lower die, but its shape is U-shaped and is mostly used for manufacturing U-shaped channel steel.

Step bending

Step bending is the multi-V bending, which can make the workpiece bend a large radius, but also can perform several small V bending in succession.

Roll forming

Roll bending allows the sheet to be bent into tubes and cones. If necessary, large radius bending can also be manufactured, which can be rolled once or multiple times simultaneously.

Wipe Bending

This is the method of bending the edge of sheet metal, and the width bending tool also determines the inner radius of the bending. The relaxation between the width die and the punch determines the result. It is also one of the working principles of finger press brake.

Conclusion: 

Stainless steel bending has become the main technology in the sheet metal working industry, and the progress of stainless steel bending technology has driven the development of the sheet metal fabrication industry. Therefore, Choose the reliable and high-end sheet metal working equipment are the basis. ZFY was founded in 2005. It has become one of the top 10 Press Brake manufacturers in China. By focusing on the research, development and production of Press brake, laser cutting machine, CNC shears, rolling machine. We aim to provide the most cost-effective mechanical solutions for global sheet metal fabrication customers and are a supplier in the Top sheet metal manufacturing industry.

It "work-hardens" a great deal - in other words, the more you deform it, the tougher it gets! Look very closely at the bits to see if they have a "grain". No, I haven't gone completely mad! As it goes through the rolling mill, it will have VERY faint stripes on it in the direction it was rolled. Obviously, if it has been polished, these will have been rubbed off but if it hasn't you might see very faint traces. If you can, fold it across the grain NOT along it. This will reduce the chance of it cracking as you fold it. As someone else has said, if you get it wrong, the chances of being able to straighten it out are almost zero. 3mm is very thick for anti-chafe. I doubt you'll be able to get an inside bend radius of much less than 3mm without the edges starting to crack (asuming it's a 90 degree bend).

 

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