An In-Depth Analysis of the Sheet Metal Fabrication Process: From Industry Evolution to Steel Pipe Bending Technology

Sheet Metal Processing Overview

Sheet metal processing, as an important metal processing material, is widely used in various industrial fields. Its processing technology encompasses multiple stages, including scribing, cutting, forming, welding, and surface treatment. Each stage is crucial and collectively determines the quality and performance of the final product. With the booming development of the automotive, telecommunications, IT, and everyday hardware manufacturing industries, sheet metal processing has become an indispensable part. Understanding the processes and techniques of sheet metal processing is increasingly important for practitioners in related industries.

Sheet metal processing refers to the process of processing raw materials such as thin metal sheets, profiles, and pipes into parts with specific shapes, dimensions, and precision using manual or mechanical methods. This process has wide applications in the fabrication of ventilation and air conditioning ducts and their components. Sheet metal parts are characterized by being lightweight, high-strength, and high-rigidity, as well as being highly malleable, having high material utilization, and requiring no additional machining. This makes sheet metal parts indispensable in daily life and industrial production, widely used in everyday items such as buckets and basins, industrial components such as ventilation ducts and material conveying pipes, and complex work such as the processing of automotive body panels.

▣ Key Materials

Common sheet metal materials include electrolytic plates, cold-rolled plates, aluminum plates, and stainless steel. These materials all possess good plasticity and high rigidity, which are crucial for ensuring processing quality and service life. Specifically, electrolytic plates include SECC(N) fingerprint-resistant plates, SECC(P), DX1, DX2, and SECD stretched plates, with a hardness range of HRB50°±5°, while stretched plates have a hardness between HRB32° and 37°. Cold-rolled plates encompass various types such as SPCC, SPCD (stretched plate), 08F, 20, 25, Q235-A, and CRS, with their hardness uniformly maintained within the HRB50°±5° range.

Aluminum plates include various types such as AL, AL(1035), AL(6063), and AL(5052). In addition, pure copper plates (such as T1, T2), hot-rolled plates, spring steel plates, galvanized steel plates, and aluminum profiles are also commonly used.

Detailed Explanation of Sheet Metal Fabrication Processes

▣ Processing Methods and Procedures

Sheet metal fabrication procedures include several key processes such as scribing, shearing, and bending, which determine the final quality and shape of the product. For example, blanking is the first step in sheet metal processing, involving cutting the material into specific shapes according to design requirements. Various methods can be used, including shearing, punching, and laser cutting. Shearing utilizes shearing equipment to precisely cut the required shape with an accuracy of over 0.2mm. Punching blanking is performed using CNC punching machines or conventional punching machines, achieving similarly high precision.

▣ Seam Joining and Applications

Seam joining is a method of connection achieved by folding and pressing the edges of the sheet metal together. It has various forms and applications. Common seam types include single flat seam, vertical seam, corner seam, combined corner seam, and snap-fit ​​seam. The application of seam joining technology in sheet metal processing is not limited to one aspect and can also be accomplished manually or mechanically.

▣ Sheet Metal Rolling and Squaring

Rolling and squaring are key processes in sheet metal forming, used to create round and rectangular ducts, respectively. Rolling, also known as bending, involves using a rotating roller to bend the sheet metal, while squaring involves bending the sheet metal into the desired square or rectangular shape.

▣ Connection Technology

In sheet metal processing, the combination of surface treatment and mechanical connection methods improves the durability and stability of products. This can be achieved by using appropriate connection methods, such as welding, riveting, threaded connections, and expansion joints, ensuring that the various parts can be smoothly assembled into a complete product.

03 Steel Pipe and Bending Technology

▣ Types and Applications of Steel Pipes

Steel pipes are divided into two main categories: seamless and welded, and are widely used in structural components and piping. Seamless steel pipes are manufactured through hot rolling, cold drawing, and extrusion, and their cross-sectional shape can be round or irregular. Welded steel pipes are made by welding steel strips and are available in galvanized and ungalvanized varieties.

▣ Pipe Bending Technology

Pipe bending technology is categorized into manual, mandrel-based, and mandrel-less methods, each suitable for different scenarios. Manual pipe bending is particularly economical and practical when bending equipment is lacking or for small-batch production. Mandrel-based pipe bending uses a mandrel to bend the pipe, preventing cross-sectional deformation during the bending process. Mandrel-less pipe bending employs a reverse deformation method, pre-applying a certain amount of reverse deformation to the steel pipe, causing it to bulge outwards before entering the bending deformation zone, thereby offsetting or reducing cross-sectional deformation during bending.