Whether you’re an OEM looking for a more effective track and trace solution, or a brand owner battling counterfeits and knock-offs, you know how much value permanent marking can add.
But you also know that, for putting indelible bar codes, serial numbers, manufacturing data, or logos directly on parts and products, there is no one-size-fits-all solution. You can’t choose the right permanent marking technology without doing some homework.
And it’s not just a matter of laser marking
vs dot peen marking (or “pin marking”
). Either can be ideal for a given situation. But the choice isn’t always obvious. The numerous alternatives in both technologies each affect performance, cost, and time, so you may have a staggering array of variables to evaluate.
Fortunately, the MECCO team
has specialized in industrial marking for more than 130 years. We’re standing by
to support your search for the optimal balance of equipment and software.
Meanwhile, to help you get up to speed, we’d like to offer a few dos and don’ts to streamline your decision-making process.
How to Select the Right Marking Technology
For many metals
and some plastics
, pin marking offers the potential for cost-effectiveness and deep, indelible impressions.
“There’s more to your decision than simply laser marking vs. pin marking,” says Conaway. “For one thing, there are several types/wavelengths of lasers, and different materials respond best to one or the other: Pulsed fiber lasers are suitable for most metals and some plastics. Short-pulse, diode-pumped solid state lasers
are ideal for metals and plastics when you need fine detail. CO2 laser marking machines
yield superior results on glass, or on organic materials like plastics, wood, rubber, paper, and cardboard.”
DO define your critical information.
Let’s talk about the permanent identifier. That’s the information you want to remain on your part or workpiece for the foreseeable future — it’s why you’re looking into permanent marking in the first place.
Information content defined clearly, early in the game, could head off expensive course corrections later on. Do give that content some extra thought: You might realize that adding a little more information could boost productivity and enhance ROI. For example, will the barcode or part number you had in mind make full use of a new device’s capacity? Or could a supplementary tracking number or logo contribute value further down the line?
Do compare notes on the content of the mark with other in-house teams, or even with customers.
Decision points: “What you say, how much you say, and how you say it — they all can impact your laser marking vs pin marking decision,” says MECCO’s Ian Conaway. “Make sure you resolve all the informational issues early in the game.”
DO focus on readability.
Readability means a mark’s effectiveness in communicating with a vision system or a human eye. It’s mostly determined by contrast and resolution.
Contrast is the difference in reflectivity or texture between the mark and the background. High contrast is essential for accurate, consistent readability. Surface finishes, marking tools, and available lighting all contribute to contrast.
Resolution, or image quality — usually expressed in dots per inch — is especially critical for detailed images like 2D barcodes; for branding elements like logos; and for small marks of all kinds. Higher is usually better, but the sweet spot for your application will depend on a variety of factors.
Decision points: According to Conaway, “In general, with the proper reader and lighting set-up, both dot peen and laser technologies can produce high-contrast, easily readable marks. But, when you also need sharpness, high-resolution laser marking is often a better choice. With both methods, choice of marking devices, surface conditions, shapes, materials, and production speeds can be critical. That’s why we produce custom sample marking that show you what each alternative would bring to your specific application.”
DO understand your materials.
Either laser or dot peen techniques can make your mark, at some level of quality, on almost any solid substrate. The deciding factor is how those technologies would interact with the materials in your specific application. Generally speaking:
- For most metals, many plastics, glass, rubber, paper, or cardboard, you’ll achieve high speed, high resolution, and high contrast with laser marking.
- For many metals and some plastics, pin marking offers the potential for cost-effectiveness and deep, indelible impressions.
DO understand your surface.
Next to materials, surface finish is one very important factor in choosing a marking technology. Applications like barcoding, where contrast and resolution are critical, illustrate why. For example, dot peen techniques are accurate enough to engrave barcodes on most metals. But cast or machined surfaces can blur dot peen details. Some manufacturers deal with uneven textures by employing laser systems that make two passes: The first to “machine” a smooth, barcode-ready blank, and the second to engrave the high-resolution, high-contrast barcode itself.
Decision points: Says Conaway, “Even small variations in the texture of a metal surface can introduce challenges you may not have anticipated. That’s why we so closely examine the finish on the actual piece you have to work with.”
DO pay close attention to marking depth.
Industry standards, Federal regulations, or customer specifications often dictate how deep your identification and traceability marks have to go. Before you make a laser marking vs. pin marking decision, consider that:
- Dot peen systems are either pneumatically or electrically fired. That’s important to note because, on mild steel, typical pneumatic systems can be set to produce marks ranging from .001" to .020" deep. On the same material, however, electrical-system marks can range from .003" to 0.012" deep.
- Some laser systems are designed to create permanent “zero-depth” oxidation markings without disturbing smooth surfaces. Others can reach depths of 0.020″ on metals, or quickly penetrate less resistant materials as deeply as 0.125″.
Decision points: “They’re not always critical, but marking depths are strictly regulated in applications like serial numbers for firearms,” says Conaway. “Both laser and dot peen devices can provide consistency and accuracy. Laser marking may be indicated when your priority is clarity or crispness, or when the surface to be marked is hard for a dot peen device to reach. On the other hand, dot peening can make a deep mark in less time.”
DON’T ignore pre- or post-marking conditions.
In an ideal world, incoming parts would have pristine surfaces; they’d take perfect impressions; and they’d go directly to the customer. But most real-life workpieces bear evidence of casting, machining, or other forming operations. They may carry oil or other residues. And, downstream, your laser or dot peen mark may endure:
- Further fabrication
- Surface treatments like painting, powder coating, galvanizing, plating, or etching
- Annealing or tempering
- Rough handling on the job
Decision points: “It’s not enough to know how laser marking works or what dot peen marking is,” says MECCO’s Conaway. “Before you evaluate your options, walk through your whole production process and imagine the part’s complete life cycle. An end-to-end list of conditions is essential when you sit down with marking-system vendors. For example:
- Additive processes: Metal parts that will be galvanized after marking are candidates for deep, bold dot peen marks.
- Heat treating: Extreme heat can erase even deep dot peen marks. But will locating your marking station downstream influence your choice of marking technology?
DON’T overlook the workplace.
Even if you’re designing a production line from the ground up, your marking system will have to fit in with the equipment, architecture, and people around it. Both laser and dot peen setups vary in size and shape. But your laser marking vs. pin marking considerations will go well beyond a system’s footprint. For example:
- Location: Will it operate near unprotected workers? Remember that laser marking sounds are generally muted, while pin marking can be noisy.
- Temperature: Parts in process, or whole areas of a plant, may be too hot for some marking equipment.
Decision points: As Conaway notes, “At the highest level, how would you describe your production space? Antiseptic clean room, or gritty, heavy-metal factory floor? If dirt and debris are inevitable, you might lean toward a rugged dot peening system. Or you might plan an enclosed space that will not only protect a laser system from harsh conditions, but also add a margin of safety for nearby workers who might risk exposure to stray laser light."
DON’T fail to consider the available “real estate”.
Shapes and sizes can be problematic. You may have to huddle with engineering, design, manufacturing, customer, or even marketing stakeholders as you determine exactly where mark should go. Before you’re through, make sure you’re clear on issues like:
- Access: How the marking device will reach the target
- Window: How much blank space the mark will require
- Impressions: How many different marks each part will undergo
- Handling: What manual or automated steps will take the part into, through, and out of the marking system
Decision points: “Sometimes the form of the part makes the decision for you,” says Conaway. “If a dot peening tool just can’t reach inside a complex shape, laser technology may be the solution. On the other hand, you might discover reasons to change the location of the mark, modify your process, or even redesign the product to accommodate the marking method you prefer.”
DON’T rule out pin marking or laser marking prematurely.
Assumptions are just as risky in the marking world as they are in any other discipline. For each technology, there’s a “Yes, but …” situation that you may not spot right off the bat. Our engineers and designers encourage an open mind: Never assume (without checking) that regulations, standards, or specs are up to date or inflexible; don’t accept hearsay or conventional wisdom that rules out either laser or pin marking technology.
Most often, all it takes is a quick email or text message to a pro who’s immersed in the subject, day in and day out.
Decision points: According to Conaway, “We’ve worked with more than one customer whose downstream processes could have obscured a mark after it was applied. One needed a deep, fast mark on a surface that later would be painted. The customer leaned toward “a nice, deep laser mark,” until we pointed out a trade-off: marking time. We showed that an N34 dot peen machine would deliver a faster mark that would be easily viewable after painting. They were delighted with the results.”
DON’T try to do it all yourself.
Of course you’ll apply your personal do’s and don’ts to your marking technology search. But your time is valuable, and the marking field is just as change-driven as your own industry. So tap into the forefront of marking expertise early, while keeping your options open. Contact the MECCO team as soon as the word “marking” enters the conversation.
Decision points: You can minimize your risk with a technology partner who:
- Defines your requirements in terms of needs, budget, and bottom-line goals
- Assesses the technical feasibility of marking your materials
- Designs custom solutions after analyzing your total operation
- Provides lifetime service to assure optimized systems and minimal downtime
That’s what we call the MECCO Experience
. By sharing it, you can maximize your peace of mind as you weigh your marking options.