How To Cut Brass

Brass is one of those ancient discoveries and has been around since about 300B.C. This binary alloy is a mixture of copper and zinc and popular for its properties of thermal conduction, corrosion resistance, strength, and its machinability. Using laser technology to cut brass in a sheet form is a method that produces very accurate and repeatable results. Some considerations on laser cutting brass:

• The brass sheet thickness and size: Some laser systems need specific sizes of uncut material. Other systems can use smaller pieces. Discussion with your service provider is needed.
• What laser system to use? Fiber lasers cut brass sheets from thicknesses of about .250mm to 1mm or higher. Plasma lasers cut brass but at much thicker grades of about an inch or thicker.
• Using nitrogen gas during the laser cutting process is needed. Using nitrogen can dissipate heat thus increasing the cut edge quality and reduce any discoloration.
• The CAD files or Computer Aided Design files are needed. These are produced in software and have extensions such as: dxf, step, gerber and others.
• The tolerance of the project. As laser systems vary in the tolerance they can hold, knowing ahead of time on what tolerance you can expect from +/- .0254mm to .0762mm, for example.
• All materials needing laser cutting, need to lay flat on the laser bed or table. This ensures a fine focus of the beam and a quality edge cut.
• Post handling-Does your project require secure packaging of each cut part? Options such as gel-paks, custom trays, foam boxes are all considerations available.
• Because of the reflectivity of brass, adjustments to the power and rate at which the laser travels are needed to prevent damage to the optics.
• As brass is a good conductor of heat careful programming of the cut path is needed to prevent heat affected zones from forming.

How To Laser Cut up to 1mm thick Brass

Laser cutting materials are much different from other technologies mainly due to the use of light and various wavelengths of it. Using diodes that take an electric current and transform photons with positive and negative charges is just the start. This resulting energy beam is the basic cutting tool. Fiber lasers vary in wavelength with systems operating from 780nm to 2050nm. For a material such as brass the tool made for fiber laser technology is a good fit. The following are some considerations and tips for cutting 1mm thick brass:

• All laser projects need a CAD or data file. These are generated in design software and have extensions such as: (dxf, step, gerber and others).
• Securing the 1mm plate on the laser bed or table. Movement of the plate can cause the cut to be inaccurate with the beam being out of focus.
• Using nitrogen gas during the laser cutting process is needed. Using nitrogen can dissipate heat thus increasing the cut edge quality and reduce any discoloration.
• Brass has good thermal conductivity, so the cut times can increase. Laser power and the number of lasers cut passes are adjusted by the operator to compensate.
• When laser cutting brass or other highly reflective materials, there can be damage to the optics. Adjustments to the CAD or laser program files to prevent damage by alternating where the beam is cutting and for what duration.

What is the best way to cut brass?

You see it often, but probably don’t think much of the way the emblem, the signage, the decorative details in a restaurant, but brass is there. Most likely, the hinges on the doors and the plumbing are never thought about, but brass is there. With countless ways brass is used, how is it manufactured into products? Specifically, how are sheets of brass cut? Parts can be stamped under extremely high pressure. But when it comes to cutting brass sheets, there are different methods to consider such as: Snips, saws in various forms, plasma cutters, laser cutting, rotary tools. The breakdown below will help guide in the type of use of each and the “best” method for cutting brass.

• Snips- or metal snips, can be found in many home garages. This tool is basically a robust pair of scissors. The hardened blades can cut thin sheets of brass, but accuracy both dimensionally and form are not there.
• Rotary tools- Again often found in the home, but also used in many metal shops, CNC and others. These types of tools can cut brass and grind the surface down. Often used in crude cutting of materials.
• Saws- A method used for crude cuts and more precision cutting, depending on the type of saw used.
  • Hand saws, hack saws- These will cut sheets of brass but leave a rough edge.
  • Table saws- With a finer tooth blade and higher quality systems, a table saw can give the user a more accurate cut and quality edge. However not suitable for tolerances below +/- 2mm.
• Fiber laser technology- This type of system would be used for much tighter tolerance and profile requirements. Fiber lasers, using wavelengths from 780nm up to 2050nm, can cut brass with a tolerance of +/- .050mm in many cases. Producing finer cut edges for use in more technical industry and medical use.
• Plasma Cutting- Using ionized gas that is forced under high pressure to cut materials is the basics of plasma cutting. Gases used vary from oxygen, argon, nitrogen and others. Cutting sheets of brass can be done, but plasma is better suited for thicker slabs of about 1 inch or thicker. It has a larger tolerance of +/- .25mm to .51mm.

Best Laser For Cutting Brass

Being a metallic alloy, brass falls under the category as a reflective, non-corrosive, highly machinable with great thermal properties, material. It is produced in many forms such as rods, tubing, sheets, rolls to produce industrial and precision parts. Methods to manipulate brass parts into a tangible product are CNC, Sawing, metal lathe, plasma cutters and laser cutters. When it comes to laser cutting, the choice for cutting brass is narrow. The following will help guide what is the best laser technology to cut brass.

• Ultraviolet lasers: Though UV laser technology has found its place in precision manufacturing, cutting brass is not recommended. The high reflectivity of brass and the power needed to cut through, do make for a great fit.
• Infrared laser Technology: IR lasers, do cut metal alloys well, especially thin gauges of stainless steel. However, brass too is challenging for this wavelength.
• CO2 lasers: This type of laser system does not cut metals well. However, for cutting non-conductive materials like wood, paper and plastics, the results can be very satisfying.
• Pico Second Lasers: Using higher power and a shorter wavelength, a Pico second laser can cut brass with an addition of assisted gas to get good cut edge quality.
• Femto Second Lasers: Using shorter wavelengths than a Pico laser, Femto systems can cut copper.
• Fiber Laser: Fiber laser technology uses a fiber optic cable as the gain medium. This silica glass cable is subjected to light sources powered from wattages of 10-50- 100-400 watts and higher for example. With beam diameters of ranging from 18um to 38um in some systems, very fine precision parts can be cut.

Cutting brass does depend on the project and requirements of each. Planning with your service provider will guide to the method that gives the best results.