Key takeaways
Tooling is the line item that causes the most hesitation in plastic display projects. The reason is understandable: it is an investment paid before any product exists, and it lands as a significant single amount. Yet it is exactly what determines the economics of the project.
This article explains what a mould is, which variables drive its cost, how the cavity-count decision is made and how amortisation is calculated, step by step.
An injection mould is a steel block carrying the negative of the part to be produced. It consists of two halves; when closed, a cavity in the shape of the part remains between them. Molten plastic is injected into that cavity under high pressure, cools and solidifies, and when the mould opens, ejectors push the part out.
Once produced, a mould runs for thousands and often hundreds of thousands of cycles. That makes it a production asset rather than an expense: for as long as it is owned, every new run carries only raw material, energy and labour cost.
A mould is not a cost item but a production asset. The question is not “how much does it cost” but “across how many parts is it divided”.
The most direct driver of mould cost. As the part grows, the mould block grows, the volume of steel to be machined increases, and the injection machine required grows too. The difference between a shelf rail and a floor stand body appears not only in steel volume but in the machine tonnage needed.
Every detail perpendicular to the mould’s opening direction — side holes, snap tabs, internal channels — requires a moving core. Each core adds a separate mechanism and a separate machining burden. Between two parts of the same size, the simple one and the cored one differ substantially in cost.
A cavity is a part-shaped void in the mould. A four-cavity mould produces four parts per cycle. As cavity count rises the mould gets more expensive but production time shortens. This is a direct speed-versus-cost balance, decided on total volume.
| Cavity count | Tooling cost | Production time | When it fits |
|---|---|---|---|
| 1 cavity | Lowest | Longest | Low volume, large parts, first run after prototype |
| 2–4 cavities | Medium | Medium | Mid-volume standard projects |
| 8+ cavities | High | Shortest | High-volume small parts (clips, fittings) |
The hardness of the tool steel determines how many cycles the mould survives. Softer, cheaper steels suffice for low-volume projects; hardened steel is required when hundreds of thousands of cycles are targeted. Abrasive materials such as glass-fibre reinforced grades wear the mould faster and push the steel selection upward.
A part’s surface mirrors the mould’s surface. A glossy finish requires the cavity to be polished to a mirror, and that is costly hand work. Textured surfaces are produced by chemical etching or laser. Transparent parts need the highest polishing class, which is why the mould for a clear bowl costs more than one for a matte part of the same size.
Amortisation is simply dividing the tooling price by the number of parts to be produced. The formula is straightforward:
Tooling share per part = Tooling price ÷ Total production volume
The table below shows how much burden the same mould carries per part at different volumes. The tooling price is illustrative; the point is to show the ratio.
| Total volume | Tooling share per part | Comment |
|---|---|---|
| 500 units | 1/500 of the tooling price | Tooling share dominates unit cost |
| 2,000 units | 1/2,000 of the tooling price | Tooling share still noticeable |
| 10,000 units | 1/10,000 of the tooling price | Tooling share drops below raw material cost |
| 50,000 units | 1/50,000 of the tooling price | Tooling share becomes negligible |
The most commonly skipped part of this calculation is that a mould is not limited to a single order. If the same stand is produced once a year for three years, the tooling share should be divided across three years of total volume, not the first order. That changes the economics of the decision entirely.
The unit cost of a plastic part consists of four items:
Only the last of these four is sensitive to volume. Because the other three are largely volume-independent, the sole reason unit cost falls with volume is the erosion of the tooling share.
There are cases where tooling investment is not the right answer, and seeing them early saves the project:
We explained step by step which stage each of these decisions belongs to in our display stand production process article.
Tooling cost looks large on its own and is usually a small item once divided by volume. To decide correctly, the question to ask is not “how much does the mould cost” but “how many parts will this mould produce and over how many years”. Share the volume and duration of your project and we can work out the right production method together — write to us.
A single figure is not possible, because cost follows part size, geometric complexity, cavity count, steel grade and surface texture. There is a large gap between a small, simple fitting mould and a large body mould with side cores. The right approach is to get a project-based price once part geometry is settled.
Mould life depends on steel grade and the material being processed. A mould made from hardened steel can run for hundreds of thousands of cycles. Abrasive materials such as glass-fibre reinforced grades shorten that, which is why steel selection follows the material.
It increases tooling cost and lowers unit production cost. A multi-cavity mould produces more parts per cycle, so machine and energy cost per part falls. In high-volume projects this saving covers the tooling difference quickly; in low-volume projects it does not.
Yes. When production runs from standard models with existing tooling, no investment is needed; brand differentiation comes through printing, colour and dressing. For short campaigns, cardboard stands or thermoforming also reduce tooling cost substantially.
To a limited extent. Removing steel — enlarging the cavity — is usually possible; adding steel, meaning thinning the part, requires welding and re-machining and is expensive. This is why locking geometry at prototype stage is critical.
Related solutions
Related equipment
Share your product, target store format and volume expectation; our technical team will propose the right solution.
