CNC Machining vs 3D Printing: Differences and Comparison

Q: What materials work best for CNC machining vs 3D printing?

CNC cuts anything machinable—aluminum, steel, titanium, brass, plastics, you name it. The part keeps full material properties since you're just cutting, not melting or fusing. 3D printing handles mostly polymers well, though metal 3D printing works for titanium and Inconel when raw material costs justify the process.

Q: Which manufacturing method produces stronger parts?

CNC wins here. Parts have 100% base material strength because the subtractive manufacturing process doesn't change the metal's internal structure. 3D printing typically delivers 10-20% strength for FDM plastic, 50-70% for metal printing, maybe 90-100% for SLS nylon if you're lucky. Depends heavily on print orientation too.

Q: How do costs compare between these manufacturing processes?

For small batches (1-25 parts), 3D printing runs $50-150 per part usually. CNC might hit $250-500 for that first piece due to setup. But make 75 parts and CNC drops to $20-80 each while 3D printing stays around $50-150. Volume completely changes the math.

Q: What production volumes favor each manufacturing technique?

Stick with 3D printing for roughly 1-50 parts where tooling costs kill your budget. Around 50-75 units, CNC starts making economic sense. Past 100 parts, CNC usually wins big on cost per piece. Fast cycle times mean cranking out 200+ parts per shift once everything's dialed in.

Q: Can these two manufacturing techniques work together?

Definitely. We do it constantly. 3D print prototypes and low-volume test units, then switch to CNC when production ramps up. Some parts even combine both—print a complex internal core, then machine the critical mating surfaces for tight fits. Gets you the best of both worlds.

Welcome to our blog for insights into different manufacturing processes.

CNC machining vs 3D printing represents two fundamentally different manufacturing techniques. CNC machining is a subtractive process that cuts away material to create parts, while 3D printing—also known as additive manufacturing—builds objects layer by layer. The 3D printing market reached USD 29.29 billion in 2025, projecting growth to USD 134.58 billion by 2034. The CNC machine market hit USD 101.22 billion in 2025, expecting to reach USD 195.59 billion by 2032.

At Lewei Precision, we’ve implemented both manufacturing methods across thousands of projects since 2008. Our ISO 9001:2015 certified facility processes over 10,000 parts monthly, giving us direct insight into when each technology delivers optimal results.

What is 3D Printing?

3D printing, known as additive manufacturing, creates parts by depositing material layer by layer from a 3D model. The manufacturing process begins with CAD software that slices designs into thin layers. The printer then builds each layer, with the process repeating until completion.

Common printing technology includes:

FDM 3D printing: Extrudes thermoplastic through heated nozzles
SLA: Cures liquid resin using UV lasers
SLS: Fuses powder with lasers
Direct metal laser sintering: Creates metal parts through powder fusion

Many 3D printers handle polymers, resins, and metal alloys. Metal 3D printing is still evolving but exceeded USD 4 billion in hardware sales during 2024. The additive process generates minimal waste since material gets added only where needed.

Lewei Precision Application: We recently produced 50 complex parts with internal cooling channels for an aerospace client using metal 3d printing. Traditional methods would have required assembly of 6 separate components.

What is CNC Machining?

CNC machining uses computer-controlled tools to remove material from solid blocks. The subtractive process includes milling, turning, drilling, and grinding operations. A CNC machine reads G-code instructions to guide cutting tools with precision down to ±0.005mm.

Primary machine types:

CNC mills: Multi-axis cutting for complex geometry
CNC turning centers: Rotating workpieces for cylindrical parts
5-axis machines: Simultaneous movement for intricate features
Grinding machines: Ultra-smooth surface finish

CNC machining uses virtually any machinable plastic or metal, from aluminum to hardened tool steel. The manufacturing method preserves 100% of the material’s native properties. Modern systems integrate AI-powered adaptive controls and digital twin monitoring.

Lewei Precision Capability: Our 45+ CNC machines produce tolerances to ±0.003mm. Last quarter, we delivered 15,000+ precision components for medical device manufacturers requiring strict dimensional accuracy.

CNC Machining vs 3D Printing

The key differences between 3D printing vs CNC machining center on process mechanics and outcomes. CNC machining cuts away material to produce parts, while 3D printing builds them additively. This fundamental distinction affects everything from part geometry possibilities to final material properties.

3D printing vs CNC comparison reveals distinct advantages:

Factor	3D Printing	CNC Machining
Process	Additive	Subtractive
Setup Time	15-30 minutes	2-8 hours
Material Strength	10-100% of bulk	100% native properties
Surface Finish	Ra 3-12 μm	Ra 0.4-3.2 μm
Tolerance	±0.1-0.5mm	±0.005-0.05mm
Waste	<5%	40-95%

CNC machining is generally preferred when dimensional accuracy and surface quality are critical. 3D printing excels for complex parts with internal features impossible to machine.

CNC Machining vs 3D Printing: Lead Cost Comparison

Cost structures for metal 3D printing vs CNC machining differ significantly. Using CNC machining typically costs USD 250-500 for simple prototype parts due to programming and tooling setup. The same part via 3D print might cost USD 50-80.

However, CNC machining offers better economics for repeat orders. Once programmed, producing many parts reduces per-unit costs dramatically. 3D printing or CNC machining decisions often hinge on quantity—the break-even point typically falls between 50-100 units depending on part complexity.

Real Lewei Data: A client’s aluminum bracket costs USD 45 via FDM 3D printing versus USD 380 for the first CNC machined unit. By unit 75, CNC cost dropped to USD 22 per part while 3D printing remained at USD 45.

CNC Machining vs 3D Printing: Speed Comparison

3D printing vs cnc machining shows different time advantages. 3D printing provides faster startup—files load in minutes and printing begins immediately. Build time depends on part size and geometry, ranging from 2-24 hours for most components.

CNC machining is often slower initially. Programming toolpaths, selecting cutters, and designing fixtures consumes 2-8 hours. Once setup completes, machining provides rapid part production. Simple parts finish in 15-45 minutes of actual cutting time.

For prototyping and end-use parts in quantities under 10 units, 3d printing is generally faster overall. Above 25 units, CNC machining often completes entire batches quicker than multiple 3D print runs.

CNC Machining vs 3D Printing: Volume Comparison

Volume dramatically affects the 3D printing vs decision. 3D printing maintains constant costs per unit—whether producing 1 or 100 parts, each requires identical material and machine time. This suits low-volume needs perfectly.

CNC machining generally becomes economical around 50+ units as fixed setup costs distribute across part production. Our facility data shows CNC unit costs dropping 60-70% between the first and hundredth part. High-speed CNC turning can produce 200+ parts per shift once fixtures are ready.

Manufacturing workflows increasingly combine both technologies. Use 3D printing for initial prototypes, then transition to CNC machining as demand scales. This approach gives you the best of both worlds.

CNC Machining vs 3D Printing: Materials Comparison

Material selection separates these two manufacturing techniques fundamentally. CNC machining can produce parts from any machinable material—aluminum, titanium, stainless steel, brass, plastics, composites. Parts maintain full native properties since the subtractive process doesn’t alter material structure.

3D printing materials continue expanding but remain limited. Polymer printing dominates with PLA, ABS, nylon, and engineering resins. Metal 3D printing is still less common than plastic printing but growing rapidly. Available metal alloys include aluminum, titanium, stainless steel, and Inconel.

Parts produced by 3D printing often show reduced strength. FDM 3D printed parts typically achieve 10-20% of bulk material strength due to layer adhesion. SLS nylon reaches 90-100%. CNC machining produces parts with consistent isotropic properties matching the source metal material.

Lewei Testing Results: Our tensile tests on aluminum parts show CNC machined specimens at 310 MPa versus 165 MPa for DMLS printed equivalents—50% strength reduction despite using identical alloy composition.

Advantages of 3D Printing and CNC Machining

Why Choose 3D Printing:

Getting prototypes made fast matters in product development. 3D printing delivers that speed—no waiting weeks for tooling or fixture design. Just send your file and parts start building within hours. The additive process wastes almost nothing compared to cutting away 95% of a metal block.

Complex geometry that makes machinists shake their heads? Not a problem for 3D printers. Internal cooling channels, organic lattice structures, parts within parts—the printer builds whatever the 3D model shows. For startups and R&D teams making 5 to 50 units, costs stay reasonable without tooling investments. Design iterations happen in days instead of months.

Why Choose CNC Machining:

When surface finish matters, CNC machining delivers. We’re talking mirror-smooth finishes around Ra 0.4 μm that 3D printing can’t touch. The machine cuts from solid material, so parts keep 100% of the base metal’s strength—no layer adhesion issues or directional weaknesses to worry about.

Tolerance requirements below ±0.05mm? CNC handles that routinely. Our machines hold ±0.003mm on critical features. Plus there’s no material restrictions—aluminum, titanium, stainless, brass, exotic alloys, engineering plastics. Whatever the application needs, CNC machining uses it. Once you’re making 50 or more parts, the economics flip hard in CNC’s favor.

Disadvantages of 3D Printing and CNC Machining

3D Printing Limitations:

Layer lines show up on printed parts—that’s just how the additive process works. Sometimes they’re barely visible, other times they need sanding or coating. 3D printing accuracy typically runs ±0.1 to 0.5mm depending on the printing technology and part size. Not terrible, but not machining-level precision either.

Strength concerns are real. FDM parts might only hit 10-20% of bulk material strength. Metal 3D printing does better at 50-70%, but that’s still weaker than machined parts. Support structures need removal and leave marks. Making many parts takes forever since each one builds individually. And forget about materials outside what your specific printer can handle.

CNC Machining Limitations:

Setup costs hurt. Programming toolpaths, designing fixtures, selecting tools—figure 2 to 8 hours before the first chip flies. That first part might cost $500 while the material cost is $15. Material waste gets ugly too, sometimes throwing away 40-95% as chips and scrap.

Tool access restricts designs. Can’t machine what the cutter can’t reach. Internal features with no outside access? Impossible. Deep pockets with narrow openings? Good luck. You need skilled machinists who know feeds, speeds, and tooling—not something learned over a weekend. Complex parts might need multiple setups and repositioning, multiplying the already high setup time.

Conclusion

Both CNC machining and 3D printing solve different problems. Need tight tolerances and smooth surfaces for production? CNC machining is better. Want to test five design variations this week without spending $10,000? Use 3D printing.

Here at Lewei Precision, we’ve run both technologies for 17 years. That’s over 500,000 parts delivered, and honestly, we use whichever method makes sense. A medical device client needed 200 titanium implants with ±0.01mm tolerances—CNC was the only option. Another customer wanted 10 housings with internal webbing for weight reduction—3D printing knocked that out in 3 days.

Markets back up both approaches. 3D printing is growing at 18.52% yearly while CNC expands at 9.9% through 2032. Companies aren’t picking sides; they’re using what’s the best way for each job. That’s exactly what we recommend.

What materials work best for CNC machining vs 3D printing?

CNC cuts anything machinable—aluminum, steel, titanium, brass, plastics, you name it. The part keeps full material properties since you’re just cutting, not melting or fusing. 3D printing handles mostly polymers well, though metal 3D printing works for titanium and Inconel when raw material costs justify the process.

Which manufacturing method produces stronger parts?

CNC wins here. Parts have 100% base material strength because the subtractive manufacturing process doesn’t change the metal’s internal structure. 3D printing typically delivers 10-20% strength for FDM plastic, 50-70% for metal printing, maybe 90-100% for SLS nylon if you’re lucky. Depends heavily on print orientation too.

How do costs compare between these manufacturing processes?

For small batches (1-25 parts), 3D printing runs $50-150 per part usually. CNC might hit $250-500 for that first piece due to setup. But make 75 parts and CNC drops to $20-80 each while 3D printing stays around $50-150. Volume completely changes the math.

What production volumes favor each manufacturing technique?

Stick with 3D printing for roughly 1-50 parts where tooling costs kill your budget. Around 50-75 units, CNC starts making economic sense. Past 100 parts, CNC usually wins big on cost per piece. Fast cycle times mean cranking out 200+ parts per shift once everything’s dialed in.

Can these two manufacturing techniques work together?