Designing for Sheet Metal Fabrication | White Paper - Protolabs

Rather than starting with a block of material, much of which will be machined away, sheet metal lets you buy what you need and use what you need. The remainder of a metal sheet is still usable, while swarf—the shavings removed in machining—must be recycled.

ACE contains other products and information you need, so please check it out.

As with many modern fabrication techniques, sheet metal manufacturing can be automated and parts produced directly from CAD models. The technology uses a variety of materials and a range of processes for shaping finished components and products. Perhaps most important, in a world of mass production, sheet metal fabrication is highly scalable. While setup for the first piece can be costly, the price per piece drops quickly as the volume increases. This is, of course, true of many processes, but cost-per-piece for sheet metal generally drops more steeply than for a subtractive process like machining.

How is Sheet Metal Being Used?

Sheet metal is cut, stamped, punched, sheared, formed, bent, welded, rolled, riveted, drilled, tapped, and machined. Hardware can be inserted into sheet metal components. The components can be brushed, plated, anodized, powder coated, spray painted, silk screened, or otherwise marked. And, of course, parts can be riveted, screwed, or welded into complex assemblies.

Like most other technologies today, sheet metal fabrication is evolving. Materials, equipment, and tooling have become more specialized than ever before. To take full advantage of sheet metal, it is critical that you leverage the correct supplier and method of manufacturing for your parts and their application. Along these lines, this white paper explores key components of sheet metal fabrication:

Want more information on sheet metal forming process? Feel free to contact us.

• Materials
• Manufacturing processes
• Design considerations
• Finishing options

Sheet Metal Fabrication Techniques

Sheet metal, by definition, starts out flat but can be shaped in many different ways to meet many different requirements. While this paper focuses on the technologies that shape sheet metal by bending it along a single axis, a variety of techniques exist for shaping the material into multi-axis forms that are not made up of flat planes or bent along a single axis. These include hot and cold forming techniques of deep drawing, hydroforming, spinning, and stamping. These are the kind of processes that create the body panels for modern vehicles, complex formed objects like metal sinks, and aluminum beverage cans. In many cases these techniques are iterative, shaping the metal by repeating the process several times to change the shape of the metal in increments.

Cold-forming processes addressed here are:

Cutting

• Shearing was long the primary way to cut sheet steel but has now been replaced by faster, more precise methods.
• A punch press can be used to punch and die sets to cut metal. This is particularly effective for cutting relatively simpler parts than would be cut with a laser or waterjet. Because it can operate at hundreds of strokes per minute, a punch press can make suitable parts quickly. Punching can also be used to make holes or other cutouts in parts. Combining punch and laser cutting allows the creation of a complex flat pattern with size-limited stamped features.
• CNC laser cutting works with jets of oxygen, nitrogen, helium, or carbon dioxide to burn away metal and produce a clean, finished edge. The speed of this process differs with the thickness of the metal, but the cut can be quite complex and, at tolerances of +/- 0.005 in. or better, is quite precise. And because there is no contact, the tool does not wear out the way a mechanical cutter does. Two types of lasers are used in sheet metal fabrication. Fiber-optic laser are used for thinner and more reflective materials to deliver precise cuts. Multi-gas or CO2 lasers are more powerful and suitable for thicker gauges.
• Photochemical machining is a process of controlled etching using CAD-generated stencils to leave a pattern that is chemically activated to remove unwanted metal.

Bending. Most metals can be bent along a straight axis using a variety of presses. The shapes of bends can range from gentle curves, like those along the vertical axis of a steel can, to sharp corners at angles above, below, or right at 90 degrees. Press brakes are used to create these relatively sharp bends. Rolling and forming methods produce open or closed single-axis curves in a continuous bending operation.

If you are looking for more details, kindly visit applications of custom sheet metal enclosures.