What is the single biggest way to reduce CNC machining cost?

Order a sensible batch rather than a single part. Setup is a fixed cost charged once per job, so a one-off carries it alone. Going from 1 to 10 parts often roughly halves the price per part, because the setup is spread across the batch while the cutting time per part stays the same.

Do tighter tolerances make CNC parts more expensive?

Yes, significantly. Tighter tolerances mean slower machining, more skilled setup and more inspection. The fix is to tighten only the features that genuinely need it — bearing seats, dowel holes, sealing faces — and leave everything else at standard (around ±0.1 mm). Applying a tight tolerance to a whole part 'to be safe' can double the price for no benefit.

Is aluminium cheaper to machine than steel?

Usually yes. Aluminium cuts faster and is kinder to tooling, so you pay for less machine time even though raw stock prices aren't wildly different. Stainless and tool steels machine slowly and wear tooling, so the same part costs more. Choose the cheapest material that genuinely meets the application.

Guides › Pricing

9 practical ways to reduce your CNC machining costs

Most buyers try to cut costs by shopping around. Usually there's more money in the design and the way you order — small changes here often save more than a different supplier ever will, and you keep the quality.

The biggest three: order a sensible batch, tighten tolerances only where they matter, and pick the cheapest material that does the job. Those alone typically move the price more than everything else combined.

1. Order a batch, not a one-off

Setup — workholding, tooling, datums, proving the program — is charged once per job and takes roughly an hour whether you want 1 part or 20. A single part carries that cost alone. Going from 1 to 10 often roughly halves the price per part. If you know you'll need spares, buying them now is far cheaper than a repeat setup later.

2. Only tighten the tolerances that matter

Standard machining tolerance (around ±0.1 mm) is fine for most features. Tight tolerances mean slower cuts, more skilled setup and more inspection. Call out ±0.02 mm on the bearing seat if you need it — but don't apply it to the whole part "to be safe". See our tolerances guide.

3. Choose the cheapest material that works

Aluminium 6082 cuts fast and is kind to tooling; stainless and tool steels machine slowly and wear tools, so they cost you twice. If the part isn't structural or corrosive-environment, aluminium or an engineering plastic may do the same job for much less. Compare in the materials guide.

4. Keep pockets shallow and radii generous

Deep, narrow pockets force long thin cutters, which must run slowly to avoid chatter. Internal corners also cost: a cutter can't make a sharp internal corner, so a tiny corner radius forces a tiny (slow) cutter. Use the largest internal radius your design allows — it lets the shop use a bigger, faster tool.

5. Avoid unnecessary thin walls

Thin walls flex and chatter, so they have to be machined gently and often need extra support. If a wall doesn't need to be 1 mm, make it 2 — it can genuinely cost less to make a slightly heavier part.

6. Reduce the number of setups

Every time a part has to be flipped or re-fixtured, that's more time and another chance to introduce error. Features on five faces need far more handling than features on two. If you can move a hole or a pocket onto a face you're already machining, do it.

7. Skip finishes you don't need

"As machined" (deburred) is included and costs nothing extra. Bead blasting, anodising, plating and painting are separate outsourced processes that add both money and lead time. Specify them where they earn their keep — corrosion protection, wear, or a part the customer actually sees.

8. Send a clean CAD file and a clear drawing

Ambiguity gets priced as risk. A proper STEP file plus a drawing showing the critical dimensions, tolerances, threads and finish means the shop can quote tightly instead of padding for the unknown — and it avoids the re-work that really costs money.

9. Don't pay for speed you don't need

Rush jobs cost more because they displace other work. If your deadline genuinely allows a standard lead time, take it. Planning two weeks ahead is one of the cheapest savings available.

See what your part actually costs

Upload your CAD file and change the material, quantity, tolerance and finish to watch the price move in real time — the fastest way to find where the money is in your design.

Get an instant quote

Frequently asked questions

Will a cheaper supplier save me more than redesigning?

Rarely. Suppliers in the same market work from broadly similar machine rates and material prices, so the spread is often modest. A design that needs half the machine time is cheaper at every supplier.

Is it worth ordering spares now?

Almost always. The setup is already paid for in this job — adding a few extra parts costs only the cutting time and material, which is why the per-part price falls so sharply with quantity.

Does a simpler shape always cost less?

Not necessarily — what matters is machine time and setups, not how the part looks. A "simple" block that needs machining on six faces to tight tolerances can cost more than a more organic-looking part done in two setups.

More: What CNC machining costs → · Choosing a material → · Tolerances & finishes →