On the surface, the concept of laser marking products seems relatively straightforward. However, there are actually various methods that can be used depending on the material and the design. Laser engraving and laser etching are two very common marking techniques used in a range of industries. If you are in the market for laser engraving or laser etching work, it is important to understand the difference between the two methods and figure out which one is best for your project.
Laser engraving and laser etching techniques are utilised across a diverse range of industries. This includes the marking of medical equipment and military machinery, as well as property identification techniques, and manufacturing applications. Commercial engraving and etching opportunities are endless. More common applications of laser engraving and etching that we may see regularly include designs on plaques, signs, jewellery and personalised gifts.
Laser etching and laser engraving are similar technologies, but the two techniques yield different results. Laser engraving creates deeper indents by vaporising material, while laser etching melts the surface to create a design. This means laser engraving is more durable and long-lasting, but also more invasive and less delicate. Depending on the project and material, one process may deliver better results than the other.
Before you commit to any laser engraving or laser engraving services you need to be familiar with the process and benefits of each. Read on to discover the advantages and disadvantages of each process and what they are commonly used for.
Is Laser Etching the Same as Laser Engraving?
While the terms can sometimes be used interchangeably, laser etching and laser engraving are not exactly the same. Although very similar, the key difference lies in the kind of transition the material goes through. In laser etching the surface of the material turns from solid to liquid through melting. The laser effectively heats the surface layer of a material without cutting into the metal. The design is then visible after the heated surface cools down.
On the other hand, laser engraving turns the surface of the material from solid to gas through vaporisation. The laser cuts a cavity into the material’s surface, creating a crevice that results in a visible design.
Laser etching is most commonly used on thin surfaces and fragile objects due to the precisione of the laser beam, while laser engraving is the preferred process for thicker materials that require a more permanent and wear-resistant design. Understanding these processes can help you make key decisions in metal fabrication, such as choosing the best material for a plaque or the right process for a particular environment.
Both processes are powered by pulsing of a laser beam, which releases sudden bursts of energy at precise intervals. For context, a 100 watt laser can release 100,000 pulses within a second, and each pulse contains 1 millijoule of energy. However, pulses in the laser etching process are spaced out further, causing the material to heat up and melt, but not vaporise.
The depth of a laser etched design is typically around 0.0001 inches (and no more than 0.001 inches). In comparison, laser engraving reaches depths of up to 0.005 – 0.020 inches.
What is Laser Etching?
Laser etching is a process in which a machine etches marks onto metal by melting the surface. This process uses a laser beam that delivers a large amount of energy to a small surface area. The surface of the material consequently melts and expands, giving laser etched designs a ‘raised’ appearance. The etched surface can look either black, white, or sometimes grey.
Once the laser beam hits the surface of the object, the material absorbs the energy it releases, and converts it into heat. In the laser etching process, the material should absorb just the right amount of energy to melt its surface at a micro level and make it expand. The increased temperature caused by the conversion of energy to heat gives the material some degree of malleability. Within milliseconds the heated material will cool down, and changes on the surface create permanent markings.
Etching is usually used to produce permanent markings such as barcodes, logos, serial numbers, and data matrix codes, among other designs.
Advantages and Disadvantages of Laser Etching
Advantages of Laser Etching
- Extremely precise results.
The precision of the laser etching process makes it ideal for designs with small details (e.g. jewellery).
- Very quick process.
The speedy process is beneficial for mass producing items or short deadlines.
- Versatile range of application.
The etching process can be done of a multitude of materials including metals, paper, wood and some acrylics.
- Effective for thick and thin materials.
This leads to greater materials efficiency and versatility in metal fabrication. Etching can be used to identify thick metal parts for industrial applications or to inscribe fine artistic designs.
- Ideal for mass production.
Laser etching provides durable results quickly and efficiently, so is often incorporated by industries for large-scale production.
- Cost effective process.
As the laser needed for etching requires less power, running costs are lower.
Disadvantages of Laser Etching
- Less durable results.
Laser etching is not as resistant to wear and tear when compared to laser engraving.
- Results can only be achieved by a fiber laser.
This limits the use of laser etching by smaller metal fabrication workshops.
What Materials Can Be Laser Etched?
Metals are the top choice for most customers using laser etching. Metals which are generally etched with a laser are aluminum, anodized aluminum, lead, magnesium, steel, stainless steel, and zinc. Plated, anodized and bare metallic surfaces are all suitable for laser etching. It’s also possible to laser etch some non-metallic materials, such as glass, polymers and ceramics.
This list is non-exhaustive, and some materials may yield better results than others, so it is recommended that you contact a laser etching expert to find out if it’s suitable for your project.
What is Laser Engraving?
Laser engraving is a process in which a laser beam vaporises a material into fumes, which in turn engraves permanent and deep marks onto an object. The laser essentially acts like a chisel, creating marks by removing layers from the surface of the material. Since the process relies on vaporisation, the laser must deliver enormous energy onto a small localised area to generate the heat required.
Laser engraving creates deep, permanent designs carved into the material surface. For that reason, it’s the preferred laser marking method for metal workpieces that will be subject to wear or harsh surface treatments.
One of the most common applications of this technology is laser engraving on stainless steel, though other steel components and aluminium are also frequently engraved. Laser engraving is also preferred for 2D codes that maintain high readability even after post-process treatments such as shotblasting, e-coating, and heat treatments.
Variations on traditional laser engraving include the use of colour compounds as well as engraving layered materials for a two-tone effect.
Advantages and Disadvantages of Laser Engraving
Advantages of Laser Engraving
- Engravings are discernable by touch as well as visually.
As engraving creates a cavity in the material’s surface, the design is more tactile.
- Deep engraving and 3D designs can be achieved with repeated passes.
Unlike etching, laser engraved designs can be deeper and more invasive, creating precise 3D forms.
- Designs are more resistant to wear and age.
A deeply carved pattern is more durable and long-lasting in harsh conditions.
- Quick and efficient compared to manual engraving.
Laser engraving is far more practical for mass-produced components.
Disadvantages of Laser Engraving
- Limited range of applications.
Laser engraving is less versatile than etching – most often used for stainless steel and other metals, there are some varieties of wood, glass and plastic that can be engraved using lasers.
- Less efficient with materials.
Vaporisation means laser engraving is less resource-efficient at scale than laser etching.
- Takes longer and uses more energy.
Engraving requires a higher-intensity laser and a longer time frame, particularly when engraving metals like stainless steel.
What Materials Can Be Laser Engraved?
Laser engraving is most commonly used on metals, particularly stainless steel, though a coating or pigment must be applied prior to engraving. Other metals such as brass and titanium can also be laser engraved.
Aside from metals, other substances that can be laser engraved include tiles, fiberglass, and organic materials such as wood and paper. The equipment required to engrave these materials can vary significantly, so most metal fabrication workshops will specialise in a particular material.
Etching vs Engraving: What Type of Machine is Used?
In laser etching and engraving, the type of machine you need to use depends more heavily on the material being marked than the actual marking process.
Since laser etching is most commonly used for marking metals, a fiber laser machine is the top choice for this process. To put it in its simplest terms, metals absorb the wavelengths of a fiber laser more efficiently than other types of lasers/machines. Therefore, whether you are engraving or etching, a fiber laser machine is the best option for marking metals.
Alternatively, if you are marking other materials, such as engraving fiberglass or wood, a CO2 laser can be used. A CO2 laser is optimised to mark thin and flat materials and can be used on fabrics, plastic, cardboard or polymers. These machines are often selected because of their high speed and great precision.
Etching vs Engraving: Which is More Durable?
Laser engraving is the best option for laser marking if your project requires durability. Due to the nature of both processes, the durability of etching and engraving lie on opposite ends of the spectrum. Laser etching is often done for more artistic and light commercial purposes, but heavy industry applications include the marking of parts and components.
Items that can be etched with a laser range from thin metallic sheets to fragile objects such as jewellery, all the way through to industrial components or custom parts that need to be tracked with a number or barcode. However, since the etching process employs a quick and precise laser to melt the surface, it does not fare as well in terms of resistance to wear,
Etched markings that are found on exposed metal usually last up to 5 or 10 years. Although this may seem like a long time, the primary drawback of laser etching is how easy it is for the marking to be obscured depending on the surrounding conditions. Unlike engraved markings which are much deeper, a layer of dirt or paint will quickly render an etching unreadable.
On the other hand, laser engraving is known for its high durability. The deeply engraved markings and designs produced by laser engraving will take a significant amount of wear and tear before the readability and visibility is reduced. As such, laser engraving is usually preferred for heavy commercial or industrial purposes where there is regular exposure to mud, sand, or water.
The more powerful a laser engraving machine is, the more permanent and deep the marks it produces can be. The markings and designs created by laser engraving are more resistant to wear, tear and post-process treatments.
Etching vs Engraving: Which is More Expensive?
Generally speaking, laser engraving costs more. This is due to the nature of the process: laser engraving requires more time, and requires more powerful technology compared to etching – However, the cost differences between the processes will vary depending on the following factors:
- Material: harder materials are more difficult to etch and engrave, which in turn increases the cost.
- Design/character size and depth: the size and depth of a design will ultimately determine the complexity of the process. Strictly speaking, the more complex a design or marking is, the higher the cost.
- Production volume: The volume of orders, as well as the number of markings required per piece, will also affect the price.
Etching vs Engraving: Which is Best for Metal?
There is no universal best laser marking process for metals, and the recommended option will depend largely on the details of the project. Both laser etching and laser engraving processes are used for metal objects and surfaces, though the exact process will vary according to the type of metal.
Laser etching is used on a huge number of materials due to the simplicity, speed, and precision of the process. Some commonly etched metals include aluminum, anodized aluminum, lead, magnesium, steel, stainless steel, and zinc.
However, laser engraving is also effective for metal surfaces and is used just as frequently. Metals that are commonly laser engraved include aluminum, brass, stainless steel, and cold rolled steel.
Laser Etching vs Laser Engraving: What Are They Used For?
Laser etching and laser engraving have similar uses and applications, spanning from light artistic work to industrial and manufacturing needs. The specifications of the project (and the level of wear the engraved part will be exposed to) will have the most influence over which method is ideal.
In the manufacturing or personalisation sphere, laser etching and engraving are both used mainly for artistic and light commercial purposes. This can include etched metal card holders, office desk name plates, wedding rings and other jewellery, and so on.
However, both etching and engraving also have applications in heavy industries such as aerospace, automotive, and transportation, often to mark thick metal parts with a code or other details. Given that laser etching is relatively long-lasting if not exposed to very harsh conditions, etching is an efficient and cost-effective way of marking metal components, particularly at scale.
While less efficient and more power-hungry, laser engraving is preferred for objects that are expected to receive heavy wear and tear, or post-process treatments. Laser engraving is often used in the transportation, energy, defense, and automotive industries.
Does Laser Etching Wear Off?
Laser etching is theoretically permanent, but the non-penetrative nature of the etching process means these markings can be damaged with time. Laser etching does not add anything to the surface of the material but rather, melts the surface itself and cools down to produce the marking. This means that the markings on the surface are made from the same material as the object they are on.
However, due to their fine nature, heavy wear and tear may scrape off, damage, or reduce the readability and visibility of the etched markings. This is why laser engraving is preferred for objects that will be subject to heavy wear.
Graham Dawe is the Managing Director and Works Manager of Kanyana Engineering. With decades of experience in the metal fabrication industry, he is dedicated to keeping Kanyana at the forefront of the sector’s technological growth. Looking beyond the process itself to holistic, integrated CAD, CAM and MRP solutions, Graham believes Australian manufacturing has an enduring place on the global stage. In Kanyana Engineering’s state-of-the-art workshop in Mandurah, WA, Graham delivers an exceptional standard of work for commercial, industrial and government clients alike.