When you want to personalize your favorite knife, laser engraving is a great way to do it.
Laser engraving is an easy, quick, and efficient way to engrave unique and intricate designs on your knife.
There are various methods to do knife engraving, and depending on the method you choose, the final appearance of your knife can vary.
This article talks about how to laser engrave knives and expert tips on improving your results.
The information discussed in this article is applicable to a wide variety of similar objects like swords, daggers, kitchen knives, and machetes.
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How to Laser Engrave Knives
A knife consists of two main parts: blade and handle. A 30W fiber laser is best suitable for shallow engravings on the metal blade, and a 50W fiber laser is recommended for deeper engravings. On the other hand, a 30 - 40W CO2 laser produces best results for engraving non-metallic handles.
Laser engraving is the process of removing layers of material to produce a pattern or design on the surface of the material.
A knife consists of two main parts, the handle, and the blade.
The handle is generally made of plastic, wood, or other non-metal material.
Whereas metals like tool steel, stainless steel, etc., are used for making the blade.
A fiber laser is generally recommended for engraving the blade as fiber lasers produce better engraving results on metals when compared to a CO2 laser.
On the other hand, a CO2 laser is readily absorbed by non-metals and is recommended for engraving the non-metallic handle.
The process of laser engraving knives consists of multiple steps.
Preparing The Design
The design is the most critical part of engraving as it determines the final look.
When designing, you need to make sure it's practical to engrave the pattern on the knife.
There are various free and paid software for laser engravers that can be used to create the design, convert the design into G-code, and provide an interface to interact with the machine.
When creating the engraving design for knives, it is recommended to take a picture of the knife and import it into the design software.
After importing the image, you can start designing over the image to make sure that the created design fits and looks good on the knife.
Setting the Optimal Parameters
The parameters of the engraving process can directly affect the quality of the engraving.
|Power||30 - 50 W|
|Engraving Speed||Around 6 ips (150mm/sec)|
|Line Interval||Around 0.005" spacing|
|Resolution||600 - 1000 DPI|
|Air Assist||Not recommended|
Optimal parameters for laser engraving stainless steel blade
The ability of a laser to remove material and produce an engraving depends upon the laser power.
Different types of metals are used for making knives, and different metals require different power settings to be engraved.
Generally, a 30 - 50W fiber laser is recommended for engraving various metals used for making knives.
Similarly, a 30 - 40W CO2 laser is capable of engraving various materials used to make the handle of the knives.
The engraving speed also affects the quality of the engraving.
For a particular power setting, as the engraving speed increases, the engraving mark gets lighter.
A perfect combination of power and speed will result in a dark mark with good contrast, no burns, and a good surface finish.
For engraving stainless steel knives with a 20W fiber laser, it is recommended to use 30% laser power at an engraving speed of 6 ips (150mm/sec) to attain a dark engraving.
The hatch pattern is an important parameter that affects the quality and contrast of the engraved pattern.
A good hatch pattern can produce excellent results with good contrast and minimizes the cycle time.
The two most commonly used hatch patterns are Uni-directional hatch and Bi-directional hatch.
Both produce good results when engraving knives, but the uni-directional hatch produces slightly better quality engraving than the bi-directional hatch at the cost of cycle time.
Furthermore, the line spacing between the hatch pattern affects the darkness of the engraved pattern.
For laser engraving stainless steel knives, it is recommended to use a tight hatch pattern with a line spacing of 0.005".
This results in a dark and uniform engraving with no gaps.
Setting a line spacing greater than 0.005" will produce a lighter mark with tiny gaps in the pattern.
A tighter hatch pattern will result in a dark engraving with less detailing and increased chances of over-burning the material.
When laser engraving, the laser does not slide through the material like a continuous knife.
Instead, it functions in a constant on/off pattern using laser pulses.
The laser frequency determines the number of laser pulses firing per second, which in turn determines the amount of laser energy absorbed by the material.
A high frequency of around 40,000Hz is recommended when engraving metals like stainless steel, tool steel, etc.
The resolution of the engraving deals with the number of dots printed per inch (DPI).
These dots are similar to the pixels in a raster image and, the higher the number of dots, the higher the detailing of the engraving will be.
The number of dots per inch (resolution) is generally limited by the spot size of the laser, as it is the smallest possible dot that the laser can print.
When engraving metal surfaces with a fiber laser, a resolution of around 600 - 1000 DPI is recommended for best results.
Air assist is generally not recommended for laser engraving as it can cause a sputter of the molten material.
This sputter spreads over the engraved surface and ruins the surface finish of the engraving.
However, when performing deep engraving on large surfaces, like a butcher's knife (cleaver), air assist can increase the speed of engraving at the cost of surface finish.
Performing Test Runs
Collectible knives and some high-quality chef knives can be extremely costly.
When working with such costly knives, it is necessary to ensure that the engraving process is fool-proof and that all the parameters are perfect.
The optimal parameters for laser engraving a particular material can vary from one laser engraving setup to another.
Therefore, it is strongly recommended to perform test runs on a scrap piece of the same material before working on the actual workpiece.
For performing test runs, it is generally advised to start with the lowest recommended settings and slowly work your way up until you get the best result.
Preparing the Workpiece
After performing the test runs and finding the optimal parameters for the material, it is time to prepare the workpiece for engraving.
When engraving the blade of a knife, it is preferable to disassemble the knife and separate the blade from the handle.
This enables to place the blade properly on the workbed and eliminates the risk of any unwanted marks on the handle.
In case the knife cannot be disassembled, it is advised to cover the handle with masking tape to avoid scratches or accidental marking.
After disassembling the blade, clean the blade with rubbing alcohol to remove any dust or microscopic impurities from the surface.
Cleaning the surface is important because the dust particles present on the surface of the blade can catch fire during laser engraving and affect the surface finish of the engraved pattern.
The next step in preparing the workpiece is to apply the engraving chemical if needed.
There are various laser marking chemicals available that can be used to enhance the contrast of the engraving and produce a dark mark.
Cover the knife blade with an even coat of the marking chemical and let it dry.
After setting the optimal parameters and preparing the workpiece, place the workpiece on the work table and begin the engraving process.
It must be noted that metals are generally very reflective.
Different Methods of Using a Laser to Personalize Knives
A laser cutter/engraver is a versatile machine that provides the ability to control the parameters of the laser to perform various different operations.
These operations differ from one another in terms of the laser power used and the depth at which it affects the surface of the workpiece material.
Laser marking is a surface phenomenon in which the laser heats and discolors the surface of the workpiece without actually removing any material.
For this process, a low-powered fiber laser can be used to oxidize the surface of the blade and produce the desired mark.
It is one of the most commonly used processes because it does not involve material removal and thus does not affect the strength of the blade.
Generally, a fiber laser is used for marking metal surfaces, and this process is also known as laser annealing.
Laser etching is similar to laser engraving, but the depth at which the laser affects the surface of the material during etching is less than a laser engraving process.
This process is often referred as surface engraving because only the top surface of the workpiece material is affected during this process.
Generally, a laser marking chemical, such as Brilliance laser ink is used to enhance the etching and produce a dark mark with high contrast.
Using a laser marking chemical can even enable a CO2 laser to produce a dark mark on the surface of the metal.
This is because, when using a laser marking chemical, the CO2 laser hits the chemical coating and fuses it with the metal underneath, thereby creating a permanent mark.
Furthermore, you can also use the laser to etch a Damasteel pattern on any knife to make it look like Damascus steel.
Deep Laser Engraving
Deep laser engraving produces the most durable and long-lasting mark on the surface of the knife.
In this process, a high-powered fiber laser is used to remove the layers of the material to make deep grooves of desired shape and pattern.
This process is generally used for engraving 3D patterns.
However, making deep grooves on the blade can weaken the knife and is generally performed on the thickest part of the blade.
The traditional method of etching metals is by applying chemicals or electricity over the surface of the metal in the desired pattern.
However, etching intricate patterns by this method is very difficult.
Laser cutters can be used to simplify this process by laser cutting the masking tape in desired patterns of complex geometries.
The laser-cut masking tape is then used to cover the area of the blade that needs to be protected from electro/chemical etching.
Metals Commonly Used for Making Knives
Depending upon the application of the knife, there are various metals used for making the blade of the knives.
Tool steel is a high-carbon, hardened steel that offers high wear resistance and more strength than stainless steel.
It has a semi-stainless property, which means it offers moderate resistance to stains and is generally used for making outdoor, tactical, and fighting knives.
These knives are generally heat-treated and can resist high temperatures.
Therefore a high-powered fiber laser (around 50W) is required to engrave these knives.
Stainless steel is one the most widely used metal for making knives.
It offers high resistance to corrosion and is therefore prominently used for makiing kitchen knives.
There are generally two types of stainless steel used for making knives.
Bare Metal Stainless Steel
The bare metal stainless steel is pure stainless steel with no protective coating over its surface.
It is generally less heat resistant than tool steel and can be engraved by a comparatively low-powered fiber laser (around 30W).
Coated Stainless Steel
Coated stainless steel is a special type of stainless steel that has a protective coating over its surface.
This coating enhances the corrosion resistance of stainless steel and prevents it from scratches.
Mainly, the coating adds color to the steel and enhances its surface finish.
Laser engraving the blades made of coated stainless steel requires less laser power than bare metal stainless steel.
A 20W fiber laser can be used to engrave coated stainless steel blades.
Damascus steel is forged steel, popularly recognized by the watery or wavey patterns on the surface of the metal.
It is not the strongest steel but is capable of retaining its sharpness for a long time.
This makes it ideal for hunting knives and kitchen knives.
The watery pattern of Damascus knives reduces the visibility of the engraved pattern and is, therefore, not recommended for engraving applications.
However, a 20W fiber laser can be used to engrave logos on the Damascus blades.
Best Laser Machine for Engraving Knives
Laser engraving knives do not require a very high-powered laser.
However, a feature-rich engraver will be preferable to reduce the cycle time and improve the quality of the engraving.
Trotec Speedmarker 300 is a desktop fiber laser engraver that offers a 7" x 7" work area with a maximum working height of 7".
It has a footprint of 23" x 34" x 26" and offers three laser power options: 20W, 30W, and 50W.
Speedmarker 300, as the name suggests, has a very high marking speed and is ideal for small-scale businesses.
It has a galvo laser system and provides a maximum marking speed of 236 ips and a maximum positioning speed of 472 ips.
The Speedmarker 300 can perform engraving on curved handles of the knives by guiding the galvo laser along the curved face of the handle without the need for a rotary axis.
It has more than 25 predefined program modules which can be used to engrave knives of different materials.
Furthermore, Trotec offers various models under the Speedmarker series that offer larger work areas.
A large work area can be used for mass production as it enables to place multiple knives on the workbed and engrave them in one go.
The OM Tech FM121-50 is a desktop laser engraver that offers a 7.9" x 7.9" work area.
It houses a 50W fiber laser that can engrave on most of the metals used to make knives.
The manual focus option of OM Tech FM1212-50 enables defocusing of the laser, which provides a greater depth of field for engraving knives with 3D contours.
It is a galvo-based laser that provides a maximum marking speed of 275 ips.
OM Tech provides a Rotary axis included in the kit which enables to engrave the curved handles of the knives.
Furthermore, 2 years parts replacement warranty and US-based support ensure satisfactory after-sale services.
A detailed review of this laser engraver can be found here - Best Fiber Laser Engraver & Cutters.
High-speed Galvanometric marking system
Rotary kit included
Glowforge Plus is a feature-rich desktop laser that houses a 40W CO2 laser.
It has a sleek look with a footprint of 38″ x 20.75″ x 8.25″ and offers a work area of 19.5” x 11”.
Although CO2 lasers cannot engrave metal, they can be used to mark or etch the blades by using a laser marking chemical.
It can also be used to engrave the non-metallic handles of the knives, making it a versatile laser engraver for small size businesses.
The inbuild camera feature enables to precisely select the engraving area on the knife and its high precision ensures excellent quality engravings.
High precision with Air-assist
Easy-to-use with built-in Cameras
With good designing skills and experience, laser engraving knives can be turned into a profitable side business.
When preparing the knife for engraving, make sure that it is completely dry and there are no traces of rubbing alcohol, as rubbing alcohol is flammable and can cause fire hazards.
Be very careful when handling the sharp knives, especially after completing the engraving process, the knife can be extremely hot, and improper handling of the hot knife can be dangerous.
Gaining experience and improving your design skills can pave the way to step into a proper knife manufacturing business where you can manufacture unique laser-cut knives with personalized engravings.
Frequently Asked Questions (FAQ)
Can we use diode lasers to engrave knives?
Yes, you can use diode lasers to engrave knives. The diode lasers are readily absorbed by metals and non-metals and can be used to engrave both the blade and handle of a knife. However, the low power of diode lasers is not suitable for performing deep engraving. They can only be used to mark the surface of the blade. Furthermore, the quality of mark produces by a fiber laser is far superior to that of a diode laser.
Can we sharpen a knife by using a laser?
Yes, you can sharpen a knife by using a laser. However, it is not recommended because the laser removes the material to produce a sharp edge. This will render the blade weak and prone to breaking.
Can we use a laser engraver to remove the rust from a knife?
Yes, you can use a laser engraver to remove the rust from a knife. Using a laser engraver to remove the layer of rust is a very effective way that is primarily used in restoring antique knives. A very low-powered laser is used to vaporize the rusty top layer of the knife without affecting the metal underneath it.