Sheet metal is among the most versatile materials in the manufacturing industry. It is made from steel, brass, copper, aluminum, nickel, tin, titanium, or other precious metals. They have a wide range of variety when it comes to thickness. It is available in plain flat sheets, etched, ribbed, embossed, perforated, and corrugated.
Moreover, its uses expand across many different industries, including transportation, aerospace, appliance manufacturing, consumer electronics, industrial furniture, machinery, and more.
How Is It Made?
Here are some of the techniques used to create body panels for complex formed objects like aluminum drinking cans. Sometimes, these sheet metal techniques are iterative, shaping the metal by repeating the process several times to change the metal’s shape in increments.
Initially, punching is similar to using a hole punch on a piece of paper. A top tool traps the material against an appropriately-shaped bottom tool and pushes through, creating a hole (or other feature). Some modern industrial sheet metal punches are CNC operated, accurate to .005” or better, and can be capable of hundreds or thousands of punches per minute. They can often hold hundreds of tools and auto-feed sheets of material.
Punching requires a different toolset for each unique feature – each diameter of a hole, square or rectangular cutout, or unique feature needs its tool. The good news is that these specialized tools are relatively cheap, and most suppliers will have a tool library with a wide variety of standard holes and features to get you started.
Sheet Metal Laser Cutting
Instead of a shop-friendly size and power, production lasers are multi-thousand-watt behemoths capable of vaporizing half-inch steel plates with .005″ precision. It can likewise offer sport auto-load capabilities and blazing fast cutting speeds.
Because of the nature of laser cutting, you can only cut straight-sided holes into sheet metal parts. That means many cool 3D features available on punched parts can’t be achieved on a laser.
The good thing is that it requires no tooling. Because there is no tooling to break, the minimum hole size is limited only by the size of your laser beam, not your material’s thickness.
It has to be noted there are a variety of materials that are hazardous to cut on a laser – painted and galvanized metals can produce gaseous cyanide or chlorine, which needs to be treated appropriately and vented. The laser is also usually more expensive than punching, making it a suitable method for low-volume, highly detailed parts but less good for higher volumes.
Flat blanks from a laser or punch are bent at low volumes utilizing a press brake, a hydraulic press that squeezes two jaws together with dozens of tons of pressure. Several alignment fixtures can be set up along the length of a press for low volumes, and an operator will manually align and form each bend in your part.
Because of the human attention needed, bends are the most expensive features to add to your part.
Once sheet metal design has been created, prototyped, and tested properly, there can be various options for turning some prototypes into low-volume production parts. Different methods at an additional expense can produce a similar part.
Picking the right would be easy if all metal shops provide the same range of capabilities. Unfortunately, they don’t, so don’t forget to ask for quotes from multiple suppliers as each will bring its expertise and capabilities.