Brass is a copper and zinc-composed material that gives a golden-yellow appearance. Engraved brass is often treated as premium by almost everyone.
Laser engraving brass involves a laser machine to place designs on the surface of the brass which requires highly efficient control and finest precision.
Apart from the laser engraver itself, engraving brass would require you to know some technical aspects and regular challenges.
For instance, brass is a highly reflective material where you cannot directly place the laser light without using a temporary coating (unless you are using a fiber laser). Alternatively, if you try to engrave brass with a CO2 laser, the reflective nature of the material will bounce back the laser beam to the laser machine itself which further causes accidents.
In this article, we will cover the variety of laser modules, challenges & ways in brass & metal laser engraving, and other important topics such as oxidization and laser engraving canvas settings.
How many types of brass are there?
Let us first discuss the variety of brass and find the differences between normal brass and laserable brass.
Depending on the density, value, weight, property composition, ductility, formability, and thermal expansion ability there are almost 60 different types of brass, and not all are laserable.
‘Laserable’ refers to a particular type that can be engraved with a laser machine with the help of a laser beam.
However, going beyond the mechanical properties, we may categorize brass into two classes one being the ‘Bare Metal Brass’ and the other being ‘Laserable with coating’.
What is Bare metal brass?
All 60 different types of brass can equally be treated as bare metal brass unless there is no coating on the upper surface of the brass.
Since bare metal brass is highly reflective, only special types of fiber laser can be used to engrave them because only the fiber lasers can produce the required laser power at brass/metal-friendly wavelength and pulse rate.
Alternatively, you cannot use a blue diode laser to engrave bare brass because the diode laser power is not at the range of brass-friendly wavelength. For example, the diode lasers produce laser power at 450 nm wavelength which cannot melt or etch the brass surface due to technical inability.
Similarly, The co2 laser produces laser power at 10,600 nm wavelength which is not appropriate for brass engraving as the proper wavelength required for brass is 1,064 nm. This is why bare brass engraving with a CO2 laser is risky since it reflects the powerful laser beam in the opposite direction before it gets engraved.
What is Coated laserable brass?
From the understanding of the prior paragraph, this is clear that you need a temporary coating on the surface of the brass so that it does not reflect the laser beam in the opposite direction.
To ease out the job, a special brass (with temporary coating above), named laserable brass sold in the market which is compatible with the CO2 lasers.
Usually, the temporary coating is made of enamel which is removed by the laser beam as per the drawings/designs. There might be different types of enamel-coated laserable brass which only helps in bringing an aesthetic golden finish to the engraved area.
Laserable brass is capable of laser engraving, drilling, bonding, and punching only. This means you cannot work with vector cuts, hotstamps, and screenprints.
Moreover, the laserable brass is fully breakproof since the glossy temporary enamel paint does not affect the brass properties. However, those are not UV-stable and flexible which means that laserable brass cannot be used as an exterior beautification tool.
Usually, the thickness of laserable brass ranges from 0.5 mm to 0.7 mm which can handle a maximum temperature of 60 degrees Celsius.
To summarize, you can only cut or engrave bare metal brass using the powerful fiber laser and the laserable brass can be worked with the CO2 lasers.
What are the Challenges of Brass Laser Engraving?
There are a few challenges when you try to engrave brass with a laser. These are:
- Shiny texture reflects the laser beam in the opposite direction simultaneously harming laser engraving efficiency and damaging the laser machine itself.
- Only fiber lasers are capable of cutting and engraving bare brass which is so expensive to afford by most people.
- Laser engraving brass would require specific CO2 laser settings that require specialized knowledge and skill.
- Manual intervention such as oxidization may be required at the post-processing stage to beautify the engraved brass.
What are the Benefits of engraving brass?
Despite the challenges, there are notable advantages of brass engraving using laser. These are:
- Engraving brass with laser is the most advanced and superior way to showcase a design on brass and the laser-like clarity cannot be achieved by any other means of tools.
- This is a non-contact process which means there is no direct contact between the laser tube and the brass. It ensures that there is no physical damage to the brass happening during the engraving or cutting process. Since the process is computer-controlled, there should not be any material loss as the laser cuts create the least possible wastage compared to the other cutting methods.
- Engraving brass with laser is the speediest process which ensures better productivity and efficiency.
- Lastly, laser engraving offers the best precision/clarity which upholds the beautification and the acceptance of an engraved piece of brass.
How many types of laser are there?
This is equally important to learn about the different types of laser so that you can choose the right laser machine for yourself. Otherwise, you may end up spending on the wrong items.
Fiber lasers are the most advanced and efficient laser to cut and engrave brass. It requires less power than the traditional CO2 lasers since it uses only one optical fiber laser beam to either etch or cut the metal.
Fiber laser produces a laser beam at a very narrow width at the absolute wavelength which helps the material to absorb the energy more effectively compared to the other types of lasers.
Laser engraving brass using a fiber laser would have several advantages as follows:
- Apart from engraving, you can cut thicker brass using a fiber laser.
- It offers faster cutting and engraving compared to other laser types.
- The spot size in the fiber laser is smaller than the CO2 laser which helps in achieving superior precision and clarity.
- Material compatibility is higher in fiber lasers. For instance, you may engrave plastics, gold, and titanium using a fiber laser which may not be possible by the CO2 lasers at any cost.
Furthermore, using only the MOPA fiber laser, you can laser engrave brass with color and this task is impossible to do with any other type of laser.
The main difference between a MOPA fiber laser and a normal fiber is that only MOPA fiber lasers are compatible to do black laser marking using aluminum oxide and the MOPA fiber laser’s pulse rise time & pulse frequency are adjustable as per the material types.
CO2 laser machine creates a powerful laser beam from a mixture of carbon dioxide, nitrogen, and other gases. CO2 lasers are also capable of engraving brass but the workpiece should be laserable brass.
The main positive side of using a CO2 laser is achieving both cutting and engraving with the same machine with a variety of materials. For example, a crafter with a CO2 laser can easily make different shapes of wood, acrylic, and other workable materials being able to engrave brass plates at the same time.
Even though the laser spot and accuracy of CO2 lasers are slightly inferior to the fiber lasers, the differences are not noticeable to normal people.
Another advantage of the CO2 laser engraver would be batch processing ability with fewer investments which is a plus point for the small engraving business.
Technically, the CO2 lasers do not engrave brass rather they only remove the upper temporary coating of the laserable brass so, this is concluded that the CO2 lasers are incapable of etching brass or similar types of materials.
Diode or blue lasers are not capable of engraving brass at all because they produce lesser laser power than the required wavelength. However, diode lasers can still engrave the laserable brass by vaporizing the top layer of temporary enamel coating which may seem like an engraved brass.
People nowadays prefer to have diode lasers since they are cheaper than the CO2 and fiber lasers.
Someone having a diversified need to cut and engrave different materials may prefer to have an all-in-one diode laser such as xTool S1 as it seems to offer almost similar services compared to other CO2 lasers.
Nowadays there is a trend that laser manufacturers are making laser machines with multiple laser heads which allows the user to access both diode and infrared lasers.
The main advantage of using hybrid lasers is that you can cut lots of materials and simultaneously engrave metal items which is the job of a fiber laser.
Indirectly, these lasers are acting as a budget-friendly alternative to fiber lasers.
Surely the powerful laser machine offers ample opportunities to cut and engrave tough materials like brass but the excess power will result in deeper engraving that does not look good.
Fiber lasers above 40 watts of power will be sufficient enough for engraving brass. However, CO2 and diode lasers would need to be above 35 watts.
We recommend not using 100% of the power while engraving as it needs to be aligned with other factors such as speed, line interval and pass counts.
Etching vs Engraving brass
The difference between etching and engraving is simple. Laser etching would melt more brass compared to the engraving. Alternatively, engraving brass would be less deep than the etching.
Technically, CO2 and diode lasers cannot perform deeper etching on brass due to their incapabilities of generating inadequate laser power.
Etching on brass can only be possible using powerful fiber lasers. You may steen engrave bare brass using the infrared lasers as said earlier but again, the infrared laser may put the design into brass but cannot melt brass to give it an appearance of deep laser marking.
Ideal settings for brass laser engraving
If you are using a CO2 laser like the xTool P2 (or, any laser having more than 40 watts of laser power) set the power to 50% to 60% if you are engraving laserable brass. Using full power is not recommended because technically you are not engraving brass but just engraving the upper enamel paint layer of it that may not absorb higher laser power.
Try using an engraving speed of 200 mm/s initially which should be perfect for engraving laserable brass plates. Make sure to use air assist and coolant-supported laser for finer engraving results.
If your target is to achieve deep engraving using a fiber laser use 100% power and 1000 mm/s engraving speed. Set 0.02 line space for the perfect results.
Frequently asked questions
What is the best laser for engraving brass?
Fiber laser is the best for bare brass engraving; however, you can use CO2 lasers for engraving coated laserable brass plates. Keep in mind, that hybrid lasers such as xTool F1 can engrave both bare brass and laserable brass because there are two lasers for different tasks.
Can a laser engraver cut brass?
Only fiber lasers can cut brass because the other types of lasers (CO2 & diode ) cannot produce the necessary power to cut brass.
Can a diode laser engrave brass?
Diode lasers can only engrave laserable brass. Technically it melts the top layer of the laserable brass but cannot engrave bare brass.
Can a CO2 laser engrave brass?
CO2 lasers can only engrave laserable brass which means they cannot engrave the bare brass as the raw brass reflects the laser power in the opposite direction.
Brass laser engraving would be easy if you could choose the right laser machine and set the appropriate settings while you engrave. We hope that the information here was useful.