Sheet Metal Bending

Sheet metal bending has many applications in various industries such as automotive, aerospace, construction, electrical and medical industries, among others. Bending can be performed by several methods including press brake bending, roll bending, rotary draw bending and free-form bending. The choice of method will depend on the material, the geometry of the part, and the desired end product. Some methods may produce tighter radius bends, while others may allow for longer bend lengths or multi-axis bending.

In press brake bending, a punch and die are used to deform the metal along a straight axis, creating a bend. Roll bending, on the other hand, uses a set of rolls to deform the metal into a curved shape. Rotary draw bending uses a mandrel to support the inside radius of the bend, while the outside surface is deformed by a die. In free-form bending, the metal is bent into a desired shape by hand or by using a jig or fixture.

Regardless of the method used, sheet metal bending requires precise control of the bending force and bend angle to ensure consistent quality and prevent cracking or breaking of the material. This is achieved through proper selection of tooling, material properties and careful control of the bending parameters.

In conclusion, sheet metal bending is a crucial process in the manufacturing industry, allowing for the creation of various shapes and forms from flat sheet metal. The choice of method, tooling and material will depend on the desired end product and the specific requirements of the job.

Welding or bonding

The process of welding sheet metal is commonly used in the automotive and metal finishing industries, requiring a combination of skill and patience from the welder. The choice of welding method depends on the type of metal and its intended use, with the three most popular techniques being gas welding, MIG welding, and TIG welding.

In addition to welding, metal bonding involves fastening two or more pieces of metal together without the use of bolts, soldering, or welding. There are various adhesives specifically designed for bonding metal, including epoxy, polyurethane, and cyanoacrylate products. These products claim to create strong metal-to-metal bonds when applied according to the manufacturer's instructions.

NC punching

CNC punching is a method of manufacturing sheet metal components using computer numerically controlled punch presses. These machines can come in either a single-head, tool rail design or a multi-tool turret design. The CNC punch press operates by moving the sheet metal in an x and y direction to accurately position it under the punching ram.

CNC punch presses typically have a processing range of 0.5mm to 6.0mm for a variety of materials including steel, zinc, galvanized, stainless steel, and aluminum. The holes punched can range from simple shapes like circles or rectangles to custom designs. Complex shapes can be created by using a combination of single hits and overlapping geometries. The machine can also punch 3D forms such as dimples, screw thread plunges, and electrical knockouts on either side of the sheet, which are commonly used in sheet metal enclosure design. Some advanced machines can also tap threads, fold small tabs, and punch sheared edges without leaving any tool marks, increasing the machine's productivity within the component cycle time. The set of instructions that guide the machine in creating the desired component is referred to as the CNC program.

Cutting

Sheet metal cutting involves separating a piece of metal by applying a force strong enough to cause the material to break. This is typically achieved through shearing processes, where a cutting tool applies a shearing force to the metal. The shearing force exceeds the material's ultimate shear strength, causing the metal to break and separate at the cut location.

Shearing processes use two tools - one above and one below the sheet metal - to apply the force. The upper tool delivers a swift blow to the metal, while the lower tool provides support. The distance between the edges of the upper and lower tools is known as the clearance, which is usually 2-10% of the material thickness. This clearance allows the material to deform plastically and fracture at an angle.

The effects of shearing on the metal vary as the cut progresses. The punch or blade impacts the metal and the material deforms and rolls over the edge. As the tool continues to penetrate, a vertical burnished zone of material forms. Finally, the material fractures at an angle, leaving a small burr at the edge. The height of each portion of the cut depends on several factors, including the sharpness of the tools and the clearance between them.

Structure

Sheet metal structures are utilized in the form of casings for containers or panels and coverings for buildings. To ensure maximum effectiveness, these structures are designed to withstand tensile loading and are constructed using materials with high strength properties. For example, vessels that are subject to internal pressures, such as gas storage tanks and reservoirs, are often shaped like spheres, cylinders, or drops and made from high-strength steel. Aluminum alloys are preferred for sheet metal structures in order to increase corrosion resistance and for use in low-temperature applications. In the construction of building enclosures, aluminum alloys are used to reduce weight and improve architectural properties and performance. The rolling method is often utilized to reduce installation work during construction. This method involves welding panels from separate sheets at a factory and coiling them into rolls for easy transport. At the construction site, the rolls are uncoiled and installed, with the connecting joints being welded afterwards.

Metal spinning