Injection Moulding in Australia: How It Compares to 3D Printing and CNC Machining
Injection moulding gives the lowest price per part for plastic components made in volume, but it needs a mould first. Compare it with the alternatives, see where it pays off, and learn how to source it.
The short answer
Choose the process by quantity and how close to production the part needs to be:
- Injection moulding for production runs in the thousands, where the mould cost is spread across many parts.
- 3D printing for early prototypes and design iterations, with nothing to tool up.
- Urethane (vacuum) casting for tens of production-looking parts from a silicone mould.
- CNC-machined plastic for small batches in real engineering plastics with tight tolerances.
Injection moulding vs 3D printing, CNC-machined plastic and urethane casting
How the four most common ways to make a plastic part compare on cost, quality and speed.
Swipe the table sideways to see every option →
| Comparison | Injection mouldingThis page | 3D printing | CNC-machined plastic | Urethane casting |
|---|---|---|---|---|
| Best for | Production runs in the thousands | Prototypes and design iterations | Small batches in engineering plastics | Tens of production-looking parts |
| Materials | Almost any thermoplastic, including glass-filled grades | Selected printable plastics and resins | Engineering plastics such as acetal, nylon and PEEK | Polyurethanes that imitate production plastics |
| Tooling cost | High: steel mould | None | None | Low: silicone mould |
| Cost per part at volume | Lowest | Highest | High | Medium |
| Part consistency | Excellent, every part from the same mould | Varies by print orientation | Very good | Good; silicone mould wears quickly |
| Surface finish | Smooth or textured, set by the mould | Layer lines, usually post-processed | Machined, tool marks possible | Smooth, copies the master |
| Time to first parts | Longest, mould build first | Shortest | Short | Short to medium |
Ratings are general guidance. Your manufacturing advisor confirms the best option for your drawing.
When does injection moulding become the cheapest option?
Drag the slider to change the order quantity and see which process gives the lowest cost per part.
Illustrative example for a small plastic enclosure, not real prices. Crossover points depend on your part's size, plastic and complexity, so your quote shows unit prices at several quantities.
Commodity vs engineering plastics
Both are moulded the same way, but they suit different jobs.
Commodity plastics
Low cost, easy to mould and colour. The usual choice for housings, covers, clips and consumer parts.
- PP, ABS, HDPE and HIPS
- Enclosures, lids, caps and trim
- Good cosmetic finish, easy to texture
Engineering plastics
Stronger, stiffer and more heat resistant, for parts that carry load or sit near an engine or motor.
- PA66 (nylon), PC, POM (acetal) and PBT
- Glass-filled grades for extra stiffness
- Gears, brackets, clips and under-bonnet parts
Relative ratings out of 5, for comparison between the two options only.
Where to get injection moulding for an Australian business
Once you have chosen injection moulding, the next decision is who builds the mould and runs the parts.
Swipe the table sideways to see every option →
| Comparison | Local Australian moulder | Overseas marketplace | RTech factory-direct |
|---|---|---|---|
| Who makes your part | The local moulder | Whichever supplier takes the job | Our own factory and toolroom |
| Mould price | Typically the highest | Varies by supplier, plus platform margin | Factory-direct, no markup |
| Price per part | Typically higher | Lower, plus platform margin | Factory-direct, no markup |
| Freight, customs and duty | Not needed | Often quoted separately | Included, one price to your door |
| Inspection report | Varies by moulder | Varies by supplier | With every order |
| Mould ownership | Usually yours | Varies by supplier | Yours, stored for reruns |
| Face-to-face visits | Easiest | Not usually possible | Dedicated advisor in Sydney |
General comparison. Individual suppliers vary.
From drawing to moulded part
One price agreed up front, and one manufacturing advisor the whole way.
Send your drawing
CAD file with quantity, plastic, colour and surface finish.
Design for moulding
Draft, wall thickness, ribs and gate position checked before steel is cut. Price within 48 hours.
Mould build and samples
Your mould is built in our toolroom and first-article samples are measured against your drawing.
Production run
Parts are moulded, checked through the run and packed to protect cosmetic faces.
Delivered duty paid
Shipped, cleared and delivered to your door with the inspection report.
Injection moulding questions
How many parts do I need for injection moulding to make sense?
It depends on the size of the part and the mould, but injection moulding usually makes sense from the low thousands of parts. Smaller quantities are often better 3D printed, urethane cast or machined.
Is injection moulding cheaper than 3D printing?
Per part, yes, once your quantity covers the cost of the mould. For a handful of prototypes, 3D printing is cheaper because there is nothing to tool up. Your quote shows the unit price at several quantities.
Who owns the injection mould?
You do. When you pay for a mould, it belongs to you. We store and maintain it for your repeat runs, and release it to you on request.
What plastics can you mould?
Most thermoplastics, including PP, ABS, PC, PA66 (nylon), POM (acetal) and glass-filled grades. Your advisor will recommend a plastic for your part's load, temperature and finish.
What tolerances can moulded parts hold?
Typical moulded dimensions are held to about ±0.1 mm, depending on the plastic and the size of the feature. Tighter features can be achieved with careful mould design, so mark the critical ones on your drawing.
How long does injection moulding take?
Most orders arrive 4–8 weeks after you approve the quote. A new mould adds mould build and sample approval before production, and your quote gives a confirmed delivery date. Repeat orders from an existing mould are faster.
Do I pay customs duty on moulded parts?
No. Prices are delivered duty paid: freight, customs clearance and import duty are included in one price, so there is no separate bill when the parts arrive.
Related guides
Ready to price your moulded part?
Send your drawing and we will come back with one price delivered duty paid, a lead time and any design notes.