ComMarker B4 Fiber Laser: What to Know Before You Buy
ComMarker links in this post are affiliate links. ComMarker has never had a say in what I write. I also design and sell jigs and accessories for this machine, and I'll point them out when they come up.
The ComMarker B4 was the first fiber laser in my shop. Mine's the 20W, and it's been here since 2023. Over two years in, it was still running as well as it did on day one. It's engraved slate, terracotta, leatherette patches, silicone coasters, stainless and anodized business cards and a pile of dog tags. This post is what I'd tell a friend who's looking at one.
The short version
A real fiber laser for metal and stone. You supply the safety and the air.
Where it shines
Fast, deep metal engraving, color on slate, a threaded table built for jigs, two lenses in the box, and LightBurn support.
Where it fights you
No enclosure and no fume extraction out of the box, and LightBurn is an extra purchase.
Best for
Anyone treating laser engraving as a business who does a lot of metal, stone and tags.
The ComMarker B4 at a glance
These are ComMarker's published numbers from its B4 product page and model comparison. The B4 comes in 20W, 30W, 50W and 100W, and ComMarker currently lists it under clearance.
What it does well
It's a real fiber laser
The small portable metal markers are usually somewhere between 2 and 5 watts. A 20W fiber can do the same work almost 10 times as fast, and it goes a lot deeper. When time is money, one minute per piece versus 20 seconds per piece really adds up over a batch. That's the whole case for a stationary fiber: speed and power.
The work area is bigger than most galvos
The 110 mm square lens is perfect for 99% of my products. Swap to the 200 mm lens and the area is huge for a galvo. Both come in the box.
A threaded table made for jigs
The table is a grid of threaded holes, which makes it very easy to attach jigs and fences. Anything you make can bolt down in the same spot every time, and batch production gets a lot faster when every piece lands where the file expects it. For one-offs, the acrylic fence pieces that come with the machine are handy too.
It's an easy machine to live with
It's not a complicated machine. The electric lift and the dual red dots make focusing quick. It came with a foot switch, which lets you treat it like an industrial machine. I don't use mine: my family is in the shop sometimes, and I don't want it firing off by accident.
It handles a wide range of materials
Where it fights you
No enclosure, no fume extraction
This isn't unique to the B4. It's typical for fiber lasers in this class. There's no shield around the beam, so the machine is meant for a space where everyone knows a laser is running and is wearing protection. It runs on a standard 110/120V outlet, so you could take it to an event, but build an enclosure first: closed on all sides except the front, and the front a solid door or laser safety panel. Most of all, keep the people around you safe, especially customers.
For fumes, even if you run an air purifier, you really need to take the air out of the building. My setup is a 6 inch duct, a blast gate and an inline fan out the wall. And wear the right glasses. You only get one pair of eyes.
LightBurn costs extra
The B4 ships with EZCAD2. Once you learn it, it's a very capable program, and it's not super hard to learn. All my designs live in LightBurn, though, so I bought the LightBurn galvo upgrade. Plan on that if you want to stay in LightBurn.
Know what rotary you're getting
The rotary I got was geared toward rings. It worked on a ring I tried, but rings aren't really my thing. It's also heavy, at least five pounds, with a big stepper motor. ComMarker sells the D69 and D80 for different diameters, so match the rotary to what you'll actually engrave.
Test every new material
Different lasers and wavelengths react differently with the same material. Silicone coasters are a good example: only some colors reacted well on my fiber. Buy sample packs and run tests before you promise a customer anything. My LightBurn test package is built for dialing in settings, and my free galvo square test checks your real working size.
What I'd add on day one
- Fume extraction vented outside, with an inline fan and a blast gate.
- Laser safety glasses rated for 1064 nm.
- An enclosure, especially if anyone else is ever in the room.
- A jig baseplate or fences so repeat jobs land in the same spot every time.
- The LightBurn galvo license if your files already live in LightBurn.
Should you buy one?
Buy it if
- You're treating laser engraving as a business and plan to grow it
- Metal, stone and tags are a big part of what you sell
- You want deep engraving, not just surface marking
- You'll build a proper setup for safety and fumes
Think twice if
- You've never used a laser and don't plan to sell. A smaller, enclosed machine will be friendlier.
- Kids or customers will be near it and you can't enclose it
- You mostly engrave wood, glass or plastic. A diode, CO2 or UV laser fits better.
Curious about ComMarker's UV laser? Read my ComMarker Omni 1 guide.
See the B4 at ComMarker (affiliate link)
Common questions
What power ComMarker B4 should I get?
ComMarker sells the B4 in 20W, 30W, 50W and 100W. Mine is the 20W, and it handles marking, deep engraving on metal and stone, and thin metal. More power means faster deep engraving and thicker metal cutting: 0.6 mm at 20W up to 3 mm at 100W, per ComMarker.
How big is the ComMarker B4's working area?
110 x 110 mm with one lens and 200 x 200 mm with the other. Both lenses come with the machine.
Does the ComMarker B4 work with LightBurn?
Yes. It ships with EZCAD2, and ComMarker lists LightBurn support. You'll need the LightBurn galvo license, which I bought because all my files live in LightBurn.
Does the ComMarker B4 have an enclosure?
No. There's no enclosure or fume extraction in the box, which is typical for fiber lasers in this class. Plan on an enclosure, laser safety glasses and extraction vented outside.
Can the B4 engrave colors on slate?
Yes. On my B4, changing speed and power took slate from light gray through tan all the way to gold. Hotter and longer makes it darker.
Do Samcraft ComMarker jigs fit the B4?
Yes. They bolt to the B4's M5 threaded table, and the Jig Baseplate lets you swap them without tools.
More from the Maker Guides
ComMarker Omni 1: the UV galvo laser
xTool F1 Ultra: fiber plus diode in an enclosure
Watch the full review on Samcraft on YouTube: When to Get a Fiber Laser, ComMarker B4 20W.
Sam
Disclosure: ComMarker links in this post are affiliate links that may earn Samcraft a commission at no extra cost to you. ComMarker has no editorial input or control over Samcraft content. Samcraft designs and sells its own accessories for ComMarker lasers, including the jig baseplate, jigs and fume extractor mentioned here. Specifications are from ComMarker's published documentation. Last reviewed September 2026.
