How to Fabricate Metal?Central Mobile Welding
We explained the fundamentals of metal fabrication in our post “What is metal fabrication all about?”. This post will focus more on the specific processes of metal fabrication and the general equipment that is involved.
First off, the basics. Metal is almost always cleaned with an angle grinder if it is to be welded, to prevent dirt from contaminating the weld pool. Only the area that will be welded needs to be cleaned. The general rule for welding edges is to clean half an inch from the edge before welding. The edges are also deburred with a belt sander to make handling safer and to prevent the burrs from damaging any equipment they pass through.
Using a Rolling Machine
For round shapes, flat sheets of metal must be inserted one at a time into a rolling machine, which is designed to form them into a perfect circle. Often times the seam will then be welded. These circular bands can then either be capped or welded to other bands of a similar diameter in order to extend their overall length.
Manual Benders vs the Brake Press
As far as bending goes, there are manual bending machines that use a handheld lever to lift and push the sheet metal into the correct bend angled. For anything thicker than 1 eighth of an inch, a press brake must be used. There are many varieties of these, but the two types are hydraulic or electric. What this machine does is basically use opposing dies that come together with extraordinary force to bend the metal. By changing the dies or how close they come to each other, one can control the shape of the radius and the angle of the bend respectively. One thing to mention about brake presses is that their design can become incredibly complex if CNC robotics are involved. These machines are programmable to perform the same bend repeatedly.
The Varieties of Cutting Operations
There are a plethora of ways to cut metal, but the equipment that you use first depends on what you’re cutting and the shape of the cut line required. Typically for straight cuts under 12 inches long, either a cold saw or band saw is used. Depending on the size of your saws, they may only be able to fit smaller material within their clamps. For straight cuts of sheet metal, the go-to machine is a shear. Shears can often cut up to a little over half an inch thick metal and anything thinner, all within a few seconds. The standard shear can cut a sheet 4 feet wide, though many shears can take much wider sheets. For complex shapes that need to be cut into sheets or plates, a CNC (computer numerical control) plasma cutter is ideal. With software, complex designs can be made on the computer and then used to instruct the plasma cutter on where to move to replicate the cut pattern. The standard cut tables for a CNC plasma setup is either 4 feet square, or 4 feet by 8 feet. For anything thicker than half an inch, your best bet is to use an oxyfuel torch. With this setup, one can easily cut steel over 6 inches in thickness. The only drawback is that it is slow and can not cut anything other than steel, including stainless steel.
The two main ways to incorporate holes into metal are either through drilling or with an ironworker. Holes can be drilled with a handheld drill, or with a drill press. The latter is much quicker and more precise. An ironworker is the fastest option as it instantaneously punches the hole, though there may be additional setup time to set the correct dies for the required diameter.
Robotics in Metal Fabrication
The metal fabrication industry has changed immensely in recent decades, and now robotics are a common theme amongst larger companies. It is now possible to acquire machines cable of drilling, operating as a brake press and even welding all-in-one. Some of these machines are even capable of moving the workpiece from one operation to another without requiring an operator to get involved. Obviously, the benefit of this technology is record speed in production times to reduce the cost of large quantities.
Above we have tried to cover the most popular and well-known tools for metal fabrication, but it is not an all-encompassing list. If you think about it, pretty much every company and household in the west uses metal in some way. This leads to a near-endless array of tools and machines to create products for so many varied applications. But the information in this post is definitely a good start to understanding the machines and processes involved in custom metal fabrication.