Insights · Cost
What drives the price of an injection mold in China?
Two suppliers can quote the same 3D file and land 80% apart — and both can be honest. The difference is specification. This is the cost anatomy we explain to buyers before they negotiate, so they compare tools instead of numbers.
Injection mold prices in China typically start around US$4,000–9,000 for a simple single-cavity production tool and commonly fall between US$9,000 and US$45,000+ for multi-cavity tools with hot runners, sliders or unscrewing action. The seven things that move the number most are cavity count, steel grade, hot runner system, part geometry and finish class, ejection complexity (sliders, lifters, unscrewing), tolerance and documentation level, and the annual volume the tool is designed for. Part size matters least.
Why “how much is a mold?” has no single answer
A plastic injection mold is not a product with a list price; it is a piece of engineering with a specification. A 4-cavity tool in 718H with a cold runner and a matt finish, and an 8-cavity tool in S136 with a valve-gate hot runner and a mirror-polished Class-A cavity for the same part, are not variations of one price — they are two different products that happen to make the same shape.
So the useful question is not “what does a mold cost?” but “what specification am I buying, and what does each part of that specification cost me?”
The seven cost drivers
1. Cavity count
Cavities multiply the expensive work: cavity and core inserts, EDM time, polishing time, fitting, cooling circuits and quality checks. Moving from 1 cavity to 4 changes the tool price roughly in the way you would expect, and 8 to 16 cavities changes it again. Cavity count should be derived from annual volume, cycle time and press tonnage — not from ambition. If your volume is 30,000 parts a year, a 16-cavity tool is usually an over-investment even though the unit price looks attractive on paper.
2. Steel grade
P20 is cheap, easy to machine and fine for a few hundred thousand shots. 718H costs more and lasts longer. NAK80 polishes to a mirror for cosmetic parts. S136 (and hardened H13 cores) resist corrosive resins and abrasive filled grades. Steel also drives machining time: harder grades consume more tool life and more EDM hours.
3. Runner system
A cold runner is basically free. A hot runner adds a purchased system, wiring, a controller and the engineering to balance it — and it also removes runner waste, shortens the cycle and improves cosmetic quality. On a technical part in ABS, a cold runner is often the right answer. On a thin-wall cosmetic closure running millions of shots, the hot runner usually pays for itself.
4. Geometry and finish class
Deep ribs, sharp internal corners, free-form surfaces and thin walls all consume machining and EDM time. Finish is the silent multiplier: a matt SPI D-class finish is quick; a mirror-polished A1–A2 Class-A surface on the same cavity can add days of hand polishing and requires a steel that will hold the polish. Textures add etching and, if the texture is customer-supplied, a texture standard to match.
5. Ejection and side action
Every undercut needs a mechanism. A slider costs significantly more than a straight-pull ejector; a lifter adds machining and fitting; an unscrewing unit with gears or a motor adds a purchased unit, more design time, more assembly time and more maintenance. This is often the single largest jump in a quotation — and the one most worth challenging during DFM, because a small design change to your part can remove an undercut entirely.
6. Tolerance and validation level
A tool that must hold critical dimensions to a tight band needs more careful machining, more measurement and a more disciplined trial process. Add CMM reports, first-article inspection, material certificates and a PPAP-style document pack and you are buying engineering hours, not steel.
7. Who does the work — and how much of it is subcontracted
This is the least visible driver and the most commercially important. A factory that machines in-house has a straight-line cost; a factory that brokers your tool to three subcontractors adds margin at every hand-off, plus transport time and a queue you cannot see. When a quote is surprisingly low, the missing cost is usually in one of the items above — most often steel grade, cavity count, hot runner brand or the number of correction rounds included.
Indicative price bands (2026, China, export quality)
| Tool type | Typical band | Usual specification |
|---|---|---|
| Prototype / bridge tool | US$1,500–5,000 | 1 cavity, P20 or aluminium, cold runner, matt finish, low volume |
| Simple production mold | US$4,000–9,000 | 1–2 cavities, P20/718H, cold runner, standard finish |
| Standard multi-cavity | US$9,000–20,000 | 4–8 cavities, 718H/NAK80, hot runner option, cosmetic finish |
| Cosmetic / thin-wall closure | US$18,000–45,000 | 8–16 cavities, NAK80/S136, hot runner, Class-A polish, tight cycle |
| Technical mechanism tool | US$25,000–70,000+ | Unscrewing, sliders, two-shot or multi-material, hardened steels |
Bands are indicative market ranges for export-quality tooling and exclude freight, duty, hot runner controllers, robotic take-out and customer-specific documentation. Every project is quoted on its own 3D data.
Compare these five points, not the total
Ask each supplier to state, in writing: (1) cavity count and layout, (2) steel grade for cavity, core and slides, (3) hot runner brand and type if included, (4) finish class and whether texture is included, and (5) how many correction rounds after T1 are included and what the documentation set contains. Two quotes that list all five can be compared in five minutes. Two quotes that list none will be compared on price alone — which is exactly how buyers end up with an under-specified tool.
Where the money actually goes on a cheap tool
- Softer steel — fine for 200,000 shots, a rebuild at 800,000.
- Fewer cooling channels or asymmetric cooling — longer cycle time for the life of the tool, and warpage you will fight forever.
- Hand-fitting instead of machined fits — works at T1, drifts as the tool wears.
- Subcontracted EDM and polishing — the schedule risk lands on you, and nobody owns the result.
- A minimal documentation package — cheap at purchase, expensive the first time your molder needs to maintain the tool.
What we do at CENTS
We quote from 3D data with a written DFM opinion, a proposed cavity layout, a stated steel grade and a stated finish class, plus a molded-part price and cycle estimate. Everything is machined in-house on 36 machines, so the quotation does not include a subcontractor margin that we cannot explain to you. And we will tell you where you can save money — which is often by changing the part, not by changing the tool.
Next step
Get a priced answer for your exact part
Send 3D data, resin, annual volume and target market. You receive a mold price, a cycle estimate, a lead-time commitment and a written DFM opinion — usually in 1–2 business days.