Pretty much every metal fabrication job we undertake starts with cutting raw material to size and shape. “Cutting” is a broad term that covers mechanical removal, (you’d call it sawing,) shearing, (which includes punching,) and melting. We have equipment for all three, so every project starts by deciding which is going to work best. Here we’ll talk about the merits of laser cutting, so you’ll know why and when this is the method to use.
Lasers Melt Things
Lasers first emerged in the early 1960’s and today are everywhere. Bar code scanners and Blu-ray players are just a couple of examples of low powered lasers unable to do much harm, (unless you stare into the beam – don’t ever do that!) But ramp up the power and you have a thin beam of light that rapidly heats and melts whatever it shines on, (with a just a few exceptions).
How Does it Work?
Our three laser cutting machines – we have a 4000 Watt Mazak plus one of 1500 Watts and another of 1000 Watts – use CO2 lasers to cut metal sheet and plate up to around 5/8” thickness. By moving the plate under the laser we can cut any kind of complex shape. If it can be drawn in CAD we can cut it. However, as this is a two dimensional process we can’t cut pockets or blind holes: the beam must pass all the way through. However, we can laser cut pipe and tube, providing it has enough space in the cross-section to let the beam defocus. (Ask for details if this is something you need.)
What are the Advantages?
Well, it’s fast and it can cut thicker material than a turret punch can handle. Linear speeds depend on type of material and thickness, but carbon steel at 3”/sec is quite feasible. Stainless steel cutting takes more heat, so it is a little slower and more challenging but still feasible.
The other big advantage is edge quality. A laser cuts beautifully square, and with an inert assist gas surrounding the beam there’s no oxidation or blackening of cut edges. That reduces, even eliminates, grinding or other prep usually needed for secondary processes like welding.
What projects don’t work with laser cutting?
Laser cutting doesn’t work on copper or brass because they reflect the infrared beam, and is difficult to use with aluminum. (Adding a coating can change this.) Some customers express concern over the heat affected zone, (HAZ – the part of the material next to the cut edge.) In the past this could be a problem, but modern lasers like ours with high quality optics produce very well-defined beams. Plus, we cut fast and use gas to cool the cut edges quickly, so HAZ isn’t really a problem.
Laser cutting isn’t right for every project, but when it is, we’ll use it.
Have a project in mind that would be a perfect for a laser? Contact us, we would love to hear about it!