When planning the production of a part or a prototype, one question often comes up — should you choose 3D printing or CNC milling? Both technologies are widely used in industry, but each suits different situations. In this article we cover the main differences and help you decide which one fits your project.

What’s the difference between the two technologies

3D printing is an additive process — the part is built up layer by layer from the chosen material, based on a 3D digital model. CNC milling, on the other hand, is a subtractive process — material is removed from a solid block using a rotating cutting tool until the desired shape is achieved. This fundamental difference shapes the strengths and limitations of each method.

When to choose 3D printing

• When the part has a complex geometry, internal channels, or organic shapes that would be difficult or impossible to machine
• When you need a prototype quickly and cost-effectively, without expensive tooling
• When only a small quantity of parts is required
• When you want to test multiple design iterations before committing to a final version — see our overview of 3D printing materials to choose the right one for your part

When to choose CNC milling

• When the part requires very tight tolerances and a high-precision surface finish
• When you need a part made from metal or another material better suited to machining
• When mechanical strength and durability are critical for the final application
• When producing larger batches where per-part cost matters more than setup time

Cost and lead time

Costs and lead times for both technologies depend on many factors — material, part size, geometry complexity, and quantity. We cover this in detail in our article on 3D printing cost — what determines the price. In general, 3D printing tends to be more cost-effective for prototypes and small batches, while CNC milling becomes more economical at larger volumes.

A combined solution

These two technologies don’t have to compete — they’re often used together. A part might be 3D printed for early-stage prototyping and design validation, then transitioned to CNC milling for final production once the design is confirmed. Combining both approaches lets you move faster while still ending up with a production-ready part.

Need advice?

Not sure which technology is right for your project? Get in touch with us and we’ll help you choose the best solution based on your part’s geometry, required quantity, and budget.