What is laser cutting?
A laser beam is a concentrated beam of light, often focusing up to 15 kw of power onto an area a few millimeters in diameter. When materials suitable for laser cutting are exposed to the beam, they vaporize.
Modern CNC laser cutting machines combine this technology with an extremely precise motion control system, allowing the laser head to cut out shapes in a wide range of metal sheet.
What metals can be laser cut?
One of the big advantages to laser cutting, is that almost any material can be cut, from thin metals to thick ones, as well as wood and certain types of plastic – although the latter two use a different process to the ones we’ll be discussing here.
Laser cutting has no problems cutting most grades of:
- Mild steel / Low Carbon steel
- Cold rolled steel
- Stainless Steel
What thicknesses can be laser cut? With the advent of Co2 laser cutting, the same accuracy and speed of thinner materials can be applied to thicker materials too.
Metals Supermarkets offers laser cutting from 0.5mm – 20mm thick, in all the materials listed above.
Advantages of laser cutting
- Speed: Once programmed, parts can be cut in a matter of seconds, much faster than the alternative methods of plasma or waterjet cutting.
- Accuracy: The control systems on modern CNC machines, including a laser cutter, are extremely accurate, meaning parts can be cut to within a tolerance of 0.2mm.
- Low cost: Because of the high speed of laser cutting, each part can be much cheaper to laser cut than using conventional processes. The low power consumption also makes them easier on the wallet.
- Cut any material: Cold cutting techniques such as machining, routing and sawing can cut thin metals but struggle with high strength materials such as AR400. Laser cutting is not affected by the material’s hardness and offers extreme precision.
Disadvantages of laser cutting
- Lead time: High power laser machines are expensive, and as such they need to be cutting parts all the time to justify their cost. This can mean lead times can be longer in some cases.
- Expensive barriers to entry: Installing a laser cutter in your facility would be great for production, but they are extremely expensive.
- Heat input: Because the laser beam vaporizes the material, it can create a localized HAZ or heat affected zone, which can require secondary processing in some use cases
- Difficulty with reflective materials: Some lasers struggle with reflective metals such as brass or polished stainless steel.
Laser cutting, especially in conjunction with bending or folding, is seen in nearly every industry in some way.
From car parts to computer cases, brackets for the medical industry to store remodeling, laser cutting can provide a great way to make brackets, signs, covers and any other light to medium weight part in metal.
Typical industries utilizing laser cutting:
- Machine manufacturing
- Auto manufacturing
- Electronics manufacturing
Prep work before laser cutting
When designing for laser cutting sheet metal, there are a few things to be aware of, to make use of the process’s advantages, as well as being clear on its limitations
- Holes: Typically, holes should not be less in diameter than the thickness of the material. This is known as a 1:1 minimum hole size, but it can differ with certain materials and processes.
- Slots: Slots can be used to align parts to each other, these should have allowance for the width of the cut, known as the kerf.
- Size: Knowing the maximum sheet size, as well as the bed size will help save costs, by allowing for less wastage. Speak to your local store for more information.
- Unsupported areas: Particularly important for stencils and signs, letters that leave ‘islands’ of material should have ‘bridges’ of sufficient thickness to hold all the parts in place. This is important in letters such as a, b, d, e, g and so on.
Types of laser cutting
There are two commercially used types of laser for metal cutting, Co2 and Fiber.
Co2 Laser cutting
The former is an older process, whereby an electrical current is passed through a chamber of Co2 gas, this excites the particles in the tube, and once focused using mirrors and lenses, produces an intense beam of light.
Co2 lasers operate at around 20% efficiency, meaning much of the power drawn by the laser tube is converted to waste heat and light, rather than laser power.
Co2 lasers range from 100’s of watts for paper, card and cloth, to 20kw for the thickest of metals.
First introduced in 2008, these use a solid state laser power generation source rather than a gas tube. Benefiting from various advances in technology these laser cutters can process a wider variety of materials than Co2.
One of the benefits of a fiber laser is their ability to cut reflective materials. This is thanks to the way the laser is transmitted to the workpiece, and makes them a better choice for brass, copper and polished stainless steels and aluminums.
The biggest benefit to the commercial operator is that a Fiber laser is much more efficient and cost effective, converting almost 80% of their input energy into cutting power. This means the parts can be made cheaper and the machines require less infrastructure changes to install.
What is the best laser for cutting metal?
Both Fiber and Co2 lasers are regularly used for cutting metal, but like most choices, each one of these laser systems has its drawbacks and benefits.
A Fiber laser can cut a large variety of materials with brass and copper having some exceptions, as many Co2 lasers cannot process certain grades of these. But these lasers are much more expensive.
That being said, Co2 lasers use more energy than a Fiber laser, and often cost more to maintain. A Fiber laser is definitely the better choice for most materials, if the budget can allow.
Both are tailored for flat rolled products; with other shapes (angles, beams, tubes), a 6-axis laser cutter is required.
Owning laser cutters vs using a service
In manufacturing there are sub-contracting companies for almost every type of service, from laser cutting and welding to assembly and large volume production.
This is because all of these services require high volumes of orders to be financially viable. They have to pay for skilled operators, upfront investments and space.
On the other hand, retaining manufacturing in-house gives flexibility and closer control on lead times and scheduling. We’ll weigh up the options below by laying out the key steps to the process:
Owning a laser
- Secure funds to purchase, or sign up to a lease, to acquire the machine.
- Find and employ trained staff to run the machine and design parts.
- Ensure it has enough work to be viable. A laser cutter can cost in excess of $500,000 to install. It will need to be running at least 8 hours a day to pay a return.
- Pay an hourly rate of around $4-10 for consumables such as gas, lenses and power.
- Cut parts on your own schedule.
Using Metal Supermarkets’ service
At Metal Supermarkets, we offer a fast turnaround time on laser cut orders, we can also advise you on part design, material selection and more. To order with us simply:
- Go to metalsupermarkets.com and get a quote, speaking to one of our experts if you need advice.
- Now you know exactly what each part costs, you can amend or order your parts.
- Receive your parts in 3-5 days.
Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985.
Visit one of our 100+ locations across North America today.