Sheet Metal Bending Machines – Rolling, Wiping, U-Bending, and Bottoming

  July 18, 2022
Yash Shah

When bending sheet metal, there are many things that you should take into consideration. There are four basic bending techniques: Rolling, Wiping, U-bending, and bottoming. Each one has its own set of advantages and disadvantages. In this article, we’ll explore all four methods and help you choose the best one for your needs. Read on to learn more! Hopefully, this article has provided you with useful information.

What is Rolling Technique in Sheet Metal Bending Machines?

A rolling method in a sheet metal bending machine should be performed with safety features. For example, the rear bending roll should be hydraulically operated and equipped with a safety trip cable. Ideally, the machine should be equipped with a safety stop button and a roll-tilting mechanism. These safety features help reduce the chance of worker injury. Additionally, the control panel should have an emergency stop button and key lock on/off power switch.

Three-roll bending machines have two fixed rolls and one adjustable roll. Two of the rolls pinch the sheet and a third one bends the metal. This makes it possible to form full tubes with little or no gap in the middle. Crowning occurs when the rolls have a slightly larger diameter in the middle than the rest of the metal. Crowning may be overcompensated with shim stock. Crowning can create a gap at the ends of thin metal. If necessary, the ends of the rolled part may be welded closed to create a tight cylinder.

How Wiping Method is done Using Sheet Metal Bending Machine?

A wipe method is used for forming bent edges on sheet metal. The sheet metal is pushed onto a wiping die and the wipe die determines the inner radius of the bend. The inner radius of the bend is also dependent on the slack between the wipe die and the punch. The inner radius of a bend should be equal to four times the thickness of the sheet, excluding any excess material.

The process of wiping is faster than folding, but it increases the risk of damaging the sheet, especially when a sharp edge is involved. Wiping is used for panel products with small profiles and is typically performed on press brakes. Wiping is one of four variations of bending, and there are many different types of bending machines. Air bending is another type of bending while bottoming and coining are two more. The machine lifts and hugs the sheet metal and bends it by pushing and pulling the die to a specified angle.

What is U-bending Method in Sheet Metal Bending Machines?

A sheet metal forming machine is a versatile tool that creates a variety of shapes from sheet metal. This process reduces the cost of making parts and improves strength while simplifying the assembly process. Its versatility makes it an ideal machine for a range of metal fabrication applications. Because of its ease of use, the U-bending sheet metal bending machine is an excellent choice for many manufacturing environments.

While operating a U-bending method, be sure to carefully align the machine to avoid warping or scratching your finished product. Before starting the bending process, clamp your sheet metal with a vice in the form blocks. Make sure to keep the bend line parallel to the guide angle of the forms. Alternatively, enlist a colleague or friend to stabilize the sheet metal. Once the sheet metal has been clamped, start tapping between the bend lines.

What is Bottoming Technique using Sheet Metal Bending Machines?

Compared to traditional bending processes, bottoming reduces spring back and improves accuracy. Typically, different bending angles and sheet thicknesses require different tools. Bottoming is done by reducing the force applied to the tool during the bending process. Below are three common examples of different bottoming techniques. Here’s a breakdown of the pros and cons of each one. The main difference between bottoming and standard bending is the process of determining the correct opening width.

During bottom bending, the punch and die are brought together so that the tip of the punch makes contact with the material. When the punch makes contact with the material, the metal is not fully bent, allowing for spring back. Because of this, it’s vital that operators understand the different bottoming methods. 

In Conclusion

Some typical sheet metal bending methods are shown above. For a variety of uses, these may be accomplished with sheet metal bending equipment. And in order to execute bends well, it is vital to comprehend these techniques.