Markforged Metal 3D Printer Reviews: An Engineer’s FAQ on 3D Printing vs. CNC Machining

I review every custom part that leaves our shop—roughly 200 unique items a year. When engineers ask whether a Markforged metal 3D printer can replace conventional machining, I usually say: it depends on the part. Here are the questions that come up most often, answered from a quality-control perspective.

1. Are Markforged printed parts as strong as machined metal?
2. What can you make with a CNC milling machine that you can't with a 3D printer?
3. When should I use laser cutting or CNC turning instead of 3D printing?
4. What does a Markforged system really cost vs. outsourcing?
5. Is Markforged certified for aerospace and defense?
6. What should I look for in a Markforged metal 3D printer review?
7. Can a Markforged replace an existing CNC operation?

Are Markforged printed parts as strong as machined metal?

It's tempting to think tensile strength is the whole story. In our 2023 supplier audit, we tested Onyx coupons from a Markforged X7 against 6061-T6 aluminum. Flat orientation reached about 80% of aluminum's yield strength, but Z-direction samples dropped to nearly half that. Fatigue behavior is different too—no ductile yield curve, no graceful deformation. (Mental note: we're still collecting data on the Metal X with 17-4 PH.) For brackets and covers, this is fine. But if a part needs to carry unpredictable loads, machined metal is the safer baseline.

What can you make with a CNC milling machine that you can't with a 3D printer?

In short: tight tolerances. A CNC milling machine can hold ±0.005 inch all day, and with proper fixturing, ±0.002 inch is reachable. A Markforged part, unless it's CNC-machined after printing, will typically land at ±0.010 inch or looser. That's a non-starter for bearing seats, mating flanges, or anything that must seal. Milling also gives you better surface finish and consistent mechanical properties. In my opinion, they're not competing; a printer makes near-net shapes, and a mill makes finished surfaces.

When should I use laser cutting or CNC turning instead of 3D printing?

For flat parts, a laser cutter is hard to beat. Say you are in Louisville and need steel brackets for a line changeover; a local laser cutting service will usually cut them from sheet in hours, at a lower per-part cost than printing. Similarly, CNC turning in Cambridge is the right process for shafts, bushings, and bush housings. What most people don't realize is that the best shops mix processes: print the complex geometry, then finish critical features on a lathe or mill. That hybrid approach is how you win in production.

What does a Markforged system really cost vs. outsourcing?

The upfront cost is substantial. Our 2024 quote for a Metal X package—including debinder, sintering furnace, and installation—landed just above $120k. I weighed that against roughly $18,000 a year in outsourced metal parts. The upside was in-house iteration; the risk was downtime, consumables, and the learning curve. I kept asking myself: is rapid prototyping worth that floor space? For us, the answer was no. But if you run high-mix, low-volume production, the math could go the other way.

Is Markforged certified for aerospace and defense?

Markforged sells into aerospace and defense, and some platforms have published process specifications. But certified is part-specific, not a blanket statement. In our Q1 2024 quality audit, we found that traceability—print logs, material lot numbers, post-processing records—matters more than brochure claims. Per FTC guidelines, claims have to be substantiated, so ask for actual test reports. If a supplier can't produce a signed certificate, that's a red flag.

What should I look for in a Markforged metal 3D printer review?

Too many reviews focus on speed and price. I'd argue repeatability is the real success metric. When reading a review, check the print orientation, layer height, and heat-treatment step. A specimen printed flat may tell you nothing about a vertical wall. Don't hold me to this, but we've seen 35% variance in Z-strength between orientations on some systems. The best reviews show failure photos, cross-sections, and micrometer readings. Also remember: a 2022 review may not describe current firmware or materials.

Can a Markforged replace an existing CNC operation?

No, and I wouldn't want it to. 3D printing complements machining, it doesn't replace it. For low-volume, complex, or custom parts—especially when you want to consolidate an assembly into one print—Markforged is excellent. But for high-volume production, repeatable tolerances, and predictable lead times, CNC milling and turning are still the backbone. What was best practice in 2020 may not apply in 2025, but the fundamentals of manufacturing have a long memory: use the right tool for the right job. Most successful shops are doing both.