Stainless Steel Bending On A Press Brake – The Ultimate Guide

What Is The Stainless Steel Bending?

Stainless steel 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.

Stainless Steel sheet bending

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 Methods 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

• Rolla-V die

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.

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.

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. KRRASS was founded in 1998. 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.