There are numerous different methods at the disposal of sheet metal fabricators these days. Some firms will specialise in just a handful of these forming techniques while others will be able to perform almost all of them. What counts with sheet metal fabrication is not so much the variety of forming methods on offer but the skill that goes into them. Unlike most manufacturers, fabricators will need to adjust their equipment to meet the needs of short runs or even one-off projects. What are the most common forming methods used in sheet metal fabrication today?
This is a forming technique that is widely used by fabricators all over the world, including Australia. Typically, a brake press will be used that applies just the right amount of pressure on a section sheet metal to alter its shape precisely. Often a die is used over which pressure is applied so that the shape of the bend can be maintained consistently with repeated processes. Only if the die becomes misshapen will the quality of this method start to fall away. When sheet metal is bent, it will remain in one constituent piece.
It may sound as though bending and curling are the same but they are not. As any good sheet metal fabrication firm would soon point out, bending forms the shape of metal whereas curling is carried out to get rid of unwanted burrs and sharp sections. Essentially, you can think of curling as a process that only happens on the edges of sheet metal rather than on entire sections of it. The aim is to make it smoother and easier to handle.
Unlike bending or curling, laser cutting alters the overall size of a section of sheet metal. It has largely replaced sawing, another forming technique, in most modern fabrication centres due to its speed and accuracy. Lasers heat up sections of metal until they become separated from one another. With this method, it is possible to cut straight lines and curves into metal. It is also often used to make holes in sections of sheet metal so that things can run through or be attached to them.
A mechanical alternative to laser cutting when a hole needs to be formed in sheet metal is punching. This method looks a bit like bending insofar as a press is used over a die. However, greater pressure is exerted such that the die punches out a hole in the metal rather than merely shaping it around it. With punching, fabricators can cut several holes into a section of sheet metal at once.