A buyer recently compared two quotes for the same turned part at a quantity of 50. Both shops quoted the same material. The machine-hour rate was nearly identical. One quote came back at 3x the other. The difference was not skill, and it was not greed — it was how each shop planned to recover its setup time. If you buy machined parts, understanding this one mechanism will change how you read every quote you receive.
The question, stated precisely
Why does the per-part price of a CNC part fall so steeply between quantity 10 and quantity 500, and what can a buyer actually do about it at low volumes?
The short answer: at low quantities, your part is not competing for machine time. It is competing for a setup. And a setup has a fixed cost that gets divided by however many parts you order.
Technical breakdown: where the money actually goes
Every CNC job carries a fixed front-end cost that exists before the first chip is cut:
- Setup and first-article proveout. Mounting fixtures, touching off tools, running and inspecting the first article. On a 3-axis part this may be 1–2 hours. On a simultaneous 5-axis part with multiple orientations and probing routines, it can easily run 4–8 hours.
- Programming and CAM. Often reused across orders once written, but it must exist for the first order.
- Tooling and workholding. Custom soft jaws, dedicated fixtures, special form tools.
Here is the key insight: these costs are per-order, not per-part. Machine time is per-part. So the per-part price is:
per-part price = (machine time × rate) + (setup + proveout + tooling) ÷ quantity
At quantity 500, a 5-hour setup adds a small amount to each part. At quantity 25, that same 5-hour setup dominates the entire quote. This is why a part that takes 3 minutes to machine does not cost 3 minutes' worth of money at quantity 25 — and why a shop quoting honestly has to show it.
The second factor is machine selection. A shop running the job on a Swiss-type lathe with a longer setup but much faster cycle time will price differently from a shop running it on a generic 3-axis mill. For small, precise turned parts, the Swiss machine wins on cycle time at almost any quantity — but only if the shop already has the bar feeding and collet workholding in place, which spreads the setup across their whole production instead of your single order.
The third factor is changeover frequency across the batch. A part needing two operations doubles the setup: machine, flip, machine again. Good shops attack this with fixtures that hold the part in one clamping — a zero-point system on the mill side, or a sub-spindle handoff on the lathe side, so the part never starts over.
A worked example
Take the same aluminum turned bushing, Ø12 mm, through both pricing regimes:
| Quantity | Cycle time | Setup recovered per part | Machine cost/part | Setup cost/part | Price trend |
|---|---|---|---|---|---|
| 10 | 3 min | 10/10 of setup | Low | Very high | Setup-dominated |
| 50 | 3 min | 5% of setup | Low | High | Crossing point |
| 500 | 3 min | 1% of setup | Low | Moderate | Machine-dominated |
| 5,000 | 2.5 min (optimized) | 0.1% of setup | Low | Negligible | Cycle-dominated |
The numbers are illustrative, but the shape is universal. Two practical consequences:
- At quantity 10–50, your leverage is not price negotiation — it is setup reduction. Ask the shop: how many operations? Can this run in one clamping? Is there existing workholding that fits?
- The quote that looks expensive at 50 may be the cheap one at 5,000, because the shop that invested in a proper fixture and a sub-spindle process scales without re-quoting. The shop that quoted cheap by running a two-operation manual process has nowhere to go.
What to ask before you accept a low-volume quote
- How many setups does my part have, and can any be eliminated?
- Is the proveout included, or billed separately?
- Will the fixture be reused if I reorder — and does the reorder price drop?
- What tolerance are you actually holding, and is it measured at quantity? (Tight features — anything at ±0.005 mm or better — add inspection time per part, not just machine time.)
A shop that answers these concretely is a shop that has actually planned your job. One that just sends a number has not.
The takeaway
Low-quantity CNC pricing is setup economics, not machine economics. You cannot negotiate away a fixed cost, but you can design it down: fewer operations, one clamping, tolerances specified only where the assembly needs them, and a shop whose machine park — Swiss-type lathes, gang-style turn-mills, 5-axis cells — already matches your part geometry so the setup lands on practiced ground.
We run exactly this kind of mixed fleet — 70 Swiss-type lathes, 50 CNC lathes and 100 five-axis machines under one roof in Shenzhen — so small-batch and volume work share the same process backbone. If you want a second opinion on a low-quantity quote, bring the drawing to chxmetal.com and we will walk through the setup line by line.
Top comments (0)