Bending steel is defined as deforming steel around a straight axis. We use force to manipulate steel until it reaches a desired angle or shape. The difference between bending versus rolling depends on the radius. For larger radii, we call it rolling, and for smaller radii, we use bending. In this post, we’ll be focusing on bending plates.
Bending Direction
The bend must always be performed perpendicular – or at most 45-degrees – to the grain lamination direction. This will increase bent resistance and reduce the risk of fractures.
A keen knowledge of Bending Direction can help protect sheet metal strength. When metal is rolled and stretched thinner and longer in a particular direction, it develops a natural “grain.” This grain has a significant impact on the nature and strength of the metal. Sheet metal fabricators must be able to identify the direction of the produced grain and counteract any defects that might develop if the metal is formed or rolled in the wrong direction. Working with the natural grain and natural ductility of the metal in the appropriate manner will help maintain its strength. In fact, the direction of the grain on a piece of rolled metal will have a direct impact on the type and degree of inside bend radius.
Ratios and proportions
The ratios and proportions of the Inside Bend Radius matter. Yes, contrary to belief, understanding the math is crucial to successful sheet metal bending or rolling. The minimum inside bend radius is directly proportionate to the thickness of the metal being formed. The thicker the material, the greater the radius. Calculating the proper inside bend radius is a key step in crafting a strong product every time. Every type of metal will have its own unique capabilities and ratios assigned for bending. Then, the next step is to identify which tool is the proper tool to complete the bend appropriately without compromising its structural integrity. It takes a highly-skilled, exceptionally trained fabricator to understand those unique specifications and produce optimal results every time.
- The curvature radius has an important impact on thickness variations. One bend with no inside radius could imply material fractures and we should always avoid this kind of bend. Below are two examples of how stretching from press compression relates to thickness reduction:
- If the radius equals the thickness of the steel plate, the stretching of the material due to the tightness of the bend causes the plate thickness to decrease up to 20%.
- If the radius equals up to 5 times the thickness, the material does not stretch nearly as much, and material thickness decreases by less than 5%.
Spring Back
The material tends to want to bend back to its original shape – this is commonly known as “spring back”. Every piece of material has to be evaluated and taken into consideration when bending. In some cases, the dies used to roll the material will bend the material further than the desired radius, but the over bend will be compensated by the material´s spring back.
Bending metal is ap skill. Anticipating how the metal will bend under pressure can be challenging. One thing is certain, however; metal is elastic. Yes, that’s right. Metal will tend to bend back toward its original shape when being bent. This is a fabrication problem that great formers will be able to overcome, however. By knowing exactly how much to over-bend the sheet or plate beyond the intended final radius, formers can compensate for the “spring back” of the metal, ensuring that the desired radius is reached in the end.
Top 8 tips for bending steel plates
Bending steel plates is a common process used in various industries, including construction, automotive, and manufacturing. Several factors should be considered when bending steel plates to ensure successful and efficient bending. The following are some critical factors to consider:
- Material Properties: Steel plates come in various grades and strengths, each with different material properties, including bending radius, yield point, and tensile strength. Consider the material properties when determining the bending process and required equipment.
- Plate Thickness: The thickness of the steel plate impacts the bending process and influences the tools and equipment required for bending. Thicker plates require more force to bend and vice versa.
- Bending Radius: The bending radius is the minimum radius of the bend in the steel plate. The chosen bending radius influences the required force of the equipment and the tools used in the bending process.
- Bending Orientation: The orientation of the bending process determines the bending direction: longitudinal or transverse. The bending orientation influences the required force, process, and equipment.
- Tempering and Heat Treatment: Tempering or heat treatment can affect the steel plate’s material properties and, therefore, the bending process. Heat-treated plates may require a more robust or specialized bending process and equipment.
- Tool Selection: Select the appropriate tools, including a press brake, mandrels, and bending dies, based on the steel plate’s material properties, thickness, and required bending radius.
- Lubrication: Proper lubrication during the bending process can reduce friction and ensure successful bending: dry or insufficient lubrication may lead to cracking or deformation of the steel plate.
- Operator Skill: The operator’s skill and experience are crucial in the bending process’s success. Ensure the operator is trained and familiar with the required equipment and process.
Summary
Consider factors such as material properties, plate thickness, bending radius, bending orientation, heat treatment, tool selection, lubrication, and operator skill when bending steel plates. By addressing these factors, you can ensure successful and efficient bending and reduce the risk of cracking or deformation of the steel plate.