EN
If you are sourcing machined plastic parts and wondering how few pieces a factory will actually make for you, you are not alone. It is one of the first questions buyers ask when they move from a prototype to a real order. The short answer: for small series plastic CNC machining, there is no fixed minimum run. A shop can machine a single part if that is what the project needs, and the practical "small series" range usually falls somewhere between one and a few hundred pieces.
This article explains what "small series" really means for plastic CNC machining, why the minimum is so low compared with molding, and how to plan your order so you get functional parts without overpaying.
There is no universal number that separates a small series from a large one. The right range depends on your part, its material, and what you are trying to achieve. In practice, most projects fall into these bands:
For a custom precision machining factory like ANOK, small series work is routine. The company machines plastic parts from one-off prototypes through to higher volumes, so the minimum run is set by your drawing and your schedule rather than by a fixed order size.
The reason the minimum is so low comes down to tooling. Injection molding needs a mold, and a mold costs thousands of dollars and takes weeks to build. That is why molders insist on large quantities — they have to spread the tooling cost across many parts.
CNC machining works differently. The cutting tool is standard, and the part is produced directly from your CAD model. There is no mold to pay for and no mold to wait on. The real cost driver in a small run is setup: reviewing the drawing, preparing the CAM program, mounting the material, and checking the first part. Those fixed costs exist whether you order one part or fifty, which is why the unit price drops as the quantity rises — but it also means a one-piece order is perfectly viable.
This makes plastic CNC machining the natural choice when you need a few parts fast, when your design is still changing, or when the volume is simply too low to justify a mold.
The decision between machining and molding usually comes down to quantity and timing. The table below summarizes the key differences for a small series:
| Factor | CNC plastic machining | Injection molding |
|---|---|---|
| Tooling cost | None | High (mold required) |
| Unit cost at low volume | Low to moderate | Very high |
| Lead time to first part | Days | Weeks to months |
| Design changes | Easy, no tooling changes | Expensive, requires mold modification |
| Material range | Wide range of stock shapes | Wide, but limited by flow properties |
| Best suited for | 1 to a few hundred parts | Thousands of parts per year |
As a rule of thumb, if your annual volume stays below a few thousand pieces, or if you expect multiple design iterations, CNC machining is almost always the smarter choice. Molding only starts to win when the volume is high enough to absorb the tooling investment.
One advantage of machining over molding is the breadth of materials available as stock. ANOK machines a full range of engineering plastics, each with different mechanical, thermal, and chemical properties:
| Material | Why it is chosen | Typical use |
|---|---|---|
| ABS | Good impact strength, easy to machine | Housings, enclosures, prototypes |
| Nylon (PA6, PA66) | Tough and wear-resistant | Bearings, rollers, structural brackets |
| POM (Acetal, Delrin) | Low friction, stable dimensions | Gears, bushings, valve parts |
| PEEK | High strength and heat resistance | Medical, aerospace, semiconductor parts |
| PC (Polycarbonate) | Impact-resistant, transparent | Lenses, transparent covers, housings |
| PTFE | Chemical resistance, low friction | Seals, gaskets, insulators |
| PMMA (Acrylic) | Optical clarity | Windows, displays, light guides |
| ULTEM | High temperature and strength | Aerospace and high-performance parts |
Material choice affects machinability more than people expect. Soft, gummy grades like PTFE need sharp tooling and controlled feeds, while glass-filled grades wear tools faster. A shop that treats plastic machining as a discipline of its own — rather than an afterthought to metal work — will hold better tolerances and deliver cleaner parts.
Even though there is no minimum quantity, the cost per part in a small series is driven by a few factors you can control:
A good partner will also flag manufacturability issues before production starts. ANOK, for example, offers DFM feedback on drawings so you can correct problems while they are still cheap to fix.
The minimum run matters less than the shop's ability to hold quality at low volume. When you evaluate a supplier, check for the things that actually affect your parts:
ANOK Precision Manufacturing is a custom precision machining factory in Shenzhen, China, ISO 9001:2015 certified and machining plastics since 2011. The shop runs 4-axis and 5-axis machining centers, holds tolerances down to ±0.002 mm, and machines everything from ABS and nylon to PEEK and ULTEM. For small series plastic CNC machining, they quote from a single piece upward, so you can validate a design before committing to a larger run.
What is the minimum order quantity for plastic CNC machining?
There is no fixed minimum. Most shops, including ANOK, will machine a single part for prototyping or validation. Small series typically range from 1 to a few hundred pieces.
Can I get just one prototype machined?
Yes. A one-off prototype is standard work in plastic CNC machining. It lets you verify geometry, fit, and function before you spend on a larger batch.
Which plastic is best for CNC machining?
For general-purpose parts, POM (acetal) is a common recommendation because it machines cleanly and holds stable dimensions. For high-temperature or high-strength applications, PEEK is the better choice.
How long does a small series take?
Lead time depends on part complexity and material availability, but small series are typically measured in days rather than weeks, since no tooling is involved.
When should I switch from CNC machining to injection molding?
When your volume is high enough that the mold cost is spread across enough parts — usually in the thousands per year — and your design is stable. Below that, machining is generally cheaper and faster.
There is no magic number for the minimum run in small series plastic CNC machining. Because no mold is required, the practical minimum is a single part, and most small series fall between one and a few hundred pieces. The real question is not "how many do I have to order" but "which shop can hold the quality I need at the volume I have." A partner with real plastic machining experience, tight tolerance capability, and flexible batch sizes will let you start small, validate your design, and scale when the time is right.
If you are planning a small series and want a straight answer on cost and lead time, send your drawing to ANOK for a quote. With CNC plastic machining services covering everything from a single prototype to production runs, you can get functional parts without being locked into a minimum quantity you do not need.