--- title: "How Deep Can a Fiber Laser Engrave? ATF .003\" Depth 30W, 50W & 100W" description: "Can a fiber laser meet ATF's .003\" serial number depth? What the rule requires, how long it takes on a 30W, 50W, or 100W, and the settings that control depth." --- # San Antonio Laser Open main menu Close main menu [ATF Compliance](https://go.salasers.com/blog/tag/atf-compliance) # How Deep Can a Fiber Laser Engrave? ATF .003" Depth on 30W, 50W & 100W [Shane Mohr](https://go.salasers.com/blog/author/shane-mohr) [Share this blog post on Twitter](https://twitter.com/intent/tweet?text=I+found+this+interesting+blog+post&url=https://go.salasers.com/blog/how-deep-can-a-fiber-laser-engrave-atf-.003-depth-tested-on-30w-50w-100w) [Share this blog post on Facebook](http://www.facebook.com/share.php?u=https://go.salasers.com/blog/how-deep-can-a-fiber-laser-engrave-atf-.003-depth-tested-on-30w-50w-100w) [Share this blog post on LinkedIn](http://www.linkedin.com/shareArticle?mini=true&url=https://go.salasers.com/blog/how-deep-can-a-fiber-laser-engrave-atf-.003-depth-tested-on-30w-50w-100w) **Short answer:** Yes. A properly set-up fiber laser, including a 30W machine, can engrave serial numbers to the ATF's .003" minimum depth on steel and aluminum. Wattage changes *how fast* you get there, not *whether* you can. In our shop, an Edge 30W reaches .003" on a 1/16"-tall serial number in 20 passes, about 2 minutes. Below is what the rule requires, how time compares across wattages, and the settings and measuring habits that keep your marks compliant. ## What the ATF Actually Requires Under 27 CFR 478.92, required firearm markings must be engraved, cast, or stamped to a **minimum depth of .003 inch**, and the serial number (and any associated license number) must be **at least 1/16 inch tall**. Depth is measured **from the flat surface of the metal, not from peaks or ridges**. NFA items carry matching requirements under 27 CFR 479.102. In plain English: .003" is a little thinner than a sheet of printer paper. The characters must be at least 1/16" tall. And any raised burr the laser leaves around the mark doesn't count toward your depth. For the bigger picture on compliance, see our [fiber laser ATF compliance guide](https://go.salasers.com/blog/fiber-laser-engraving-for-firearms-atf-compliance-guide). *This is general information, not legal advice. If you're unsure whether your work requires marking, or how, check with the ATF or an attorney who handles FFL compliance.* ## How Long It Takes: Edge 30W vs 50W vs 100W We timed a standard 1/16"-tall serial number on steel on our Edge 30W. Higher-wattage machines remove more metal per pass, so they reach the same depth in fewer passes. The 50W and 100W figures below are **estimates based on that measured 30W result**, not separate shop measurements. | Machine | Passes to .003" | Time to .003" | Basis | | --- | --- | --- | --- | | Edge 30W | 20 | About 2 minutes | Measured in our shop | | Edge 50W | About 12 to 15 | About 1 to 1.5 minutes | Estimate | | Edge 100W | About 6 to 10 | About 40 seconds to 1 minute | Estimate | Measured on 1/16"-tall characters in steel. Why the estimates are ranges: more power removes more metal per pass, but doubling wattage doesn't exactly halve the passes. Heat buildup, debris, and the cleaning passes you still need all add time no matter the machine. Your actual results also depend on the length of the serial, the material, your lens, and your settings. What this means for buying: for one serial at a time, the difference between 2 minutes and 1 minute rarely matters. It starts to matter at volume. If you mark 50 serials a day, a faster machine can save you roughly an hour of machine time daily. ## Does a MOPA Laser Engrave Deeper? Not necessarily. MOPA fiber lasers let you adjust pulse width, which is excellent for color marking on stainless, clean white marks on anodized aluminum, and marking plastics. For raw depth, what matters most is pulse energy, total power, and the number of passes. A standard Q-switched fiber source is the proven workhorse for deep engraving on gun steel and aluminum. Choose MOPA if color and plastics are a big part of your work, not because you think it's required for ATF depth. ## Settings That Control Depth - **Passes.** Depth builds a little with each pass. This is the main lever. - **Lens (field) size.** A smaller field lens focuses the beam into a tighter spot, which concentrates energy and cuts depth faster. A larger lens covers more area but engraves shallower per pass. - **Hatch angle.** Rotating the fill angle each pass gives a flatter, cleaner floor than repeating the same angle. - **Cleaning passes.** A quick, low-power pass every few cycles clears debris so the next passes cut metal instead of re-melting residue. - **Focus as you go deeper.** On deep work, lowering focus slightly as material is removed keeps the beam sharp at the bottom of the mark. - **Speed and frequency.** Slower speed and the right frequency for your source put more energy into the metal. Dial these in with test cards, not guesswork. ## How to Measure Depth Correctly Use a depth gauge or dial indicator with a fine tip, or a profilometer if you have access to one. Zero it on the flat, untouched surface beside the mark, then measure inside the characters. If the laser raised a burr around the edges, remove it before measuring, because the ATF measures from the flat surface, not the ridge. Keep a simple log of material, settings, and measured depth for each job type. It makes repeat work faster and gives you a record if anyone asks. ## Coated Parts and Polymer Frames **Coated parts:** On anodized or Cerakoted parts, the depth requirement is about the metal. Measure from the metal surface, and plan your workflow so the coating doesn't fill in or hide the serial. **Polymer frames:** The regulation measures depth from the flat surface of the metal, and many polymer-frame pistols carry their serial on an embedded metal plate or insert. If you need to mark directly on polymer, confirm with the ATF that your approach meets the requirements before you put it into production. ## Which Edge Is Right for Your Shop? - **Edge 30W:** A strong fit for shops doing occasional serial work alongside custom engraving. - **Edge 50W:** A strong fit for shops that mark serials every day or run mixed production. - **Edge 100W:** Built for high-volume compliance marking and deeper relief engraving. Comparing other brands too? Our [gun engraving laser buyer's guide](https://go.salasers.com/blog/best-laser-engraver-for-guns-in-2026-the-complete-buyers-guide) lays out the options side by side. Every Edge system ships with LightBurn software, multiple lenses, a full supply kit, and a 2-year warranty. Just as important: buying the right machine is half the job. Our 5-day, in-person [Spark training](https://salasers.com/spark/) covers machine setup, LightBurn workflow, and real-world settings so you're producing compliant marks with confidence, not guessing. ## Frequently Asked Questions ### Can a 30W fiber laser engrave to ATF depth? Yes. In our shop, an Edge 30W engraves a 1/16"-tall serial number on steel to .003" in 20 passes, about 2 minutes. Higher-wattage machines get there faster, but a 30W does the job. ### How many passes does it take to reach .003"? On our Edge 30W, 20 passes on steel with our settings. Higher wattage needs fewer. Your number will depend on your lens, material, and settings, so dial in a recipe for each material and verify depth with a gauge. Always measure rather than assume. ### Can a CO2 laser engrave ATF-compliant serial numbers? No. CO2 lasers are built for wood, acrylic, leather, and other non-metals. They can't engrave bare metal to a meaningful depth. For serial numbers on firearms, you need a fiber laser. ### Does the burr around a laser mark count toward depth? No. The ATF measures depth from the flat surface of the metal, not from raised peaks or ridges. Remove the burr and measure from the flat surface. ### Do I need training to engrave compliant serial numbers? Training isn't legally required, but it's the fastest way to avoid scrapped parts and non-compliant marks. Spark training includes hands-on setup and settings work on fiber lasers. ## Talk to a Laser Specialist SA Laser is a veteran-owned company in San Antonio, Texas, selling and supporting fiber and CO2 laser systems since 2012. If you're choosing a laser for firearm engraving, [book a call](https://salasers.com/forms/) or reach us at (888) 964-3568. We'll help you match the machine to your volume, materials, and budget. ### Leave a Comment ## Related Articles ### [Achieving Precision Cutting with 30W Fiber Lasers](https://go.salasers.com/blog/achieving-precision-cutting-with-30w-fiber-lasers) Unlock the secrets behind achieving unparalleled precision in cutting applications with 30W fiber lasers. [Shane Mohr](https://go.salasers.com/blog/author/shane-mohr) [Read More](https://go.salasers.com/blog/achieving-precision-cutting-with-30w-fiber-lasers) ### [Best Laser Engraver for Guns in 2026: A Gunsmith's Guide to Choosing the Right Machine](https://go.salasers.com/blog/best-laser-engraver-for-guns-in-2026-a-gunsmiths-guide-to-choosing-the-right-machine) Selecting the right laser engraving system for firearms customization requires understanding power requirements, precision capabilities, and compliance with federal... [Shane Mohr](https://go.salasers.com/blog/author/shane-mohr) [Read More](https://go.salasers.com/blog/best-laser-engraver-for-guns-in-2026-a-gunsmiths-guide-to-choosing-the-right-machine) #### About - Menu Item One - Menu Item Two - Menu Item Three #### Services - Menu Item One - Menu Item Two - Menu Item Three #### News - Menu Item One - Menu Item Two - Menu Item Three Follow us on Facebook Follow us on LinkedIn Follow us on Twitter Follow us on Instagram ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Shane Mohr", "url" : "https://go.salasers.com/blog/author/shane-mohr" }, "dateModified" : "2026-10-07T19:19:51.010Z", "datePublished" : "2026-10-07T19:15:28.000Z", "headline" : "How Deep Can a Fiber Laser Engrave? 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