Mold prices are not random. Every figure on a tooling quotation traces back to six measurable inputs — part size, cavity count, steel grade, machining hours, runner type and surface specification. Once you can read those six, you can compare quotes instead of collecting them.
Tooling is usually the single largest line item in a plastic part programme, and the one with the least transparency. Two suppliers can quote the same part at USD 8,000 and USD 32,000 with identical drawings in hand, and both can be technically correct — the difference sits in cavity count, steel grade, and how much of the mold was designed versus copied from a previous job.
This article breaks the number down. It gives indicative price bands for common categories, explains what each cost line actually covers, and ends with the checklist we use when reviewing a quotation for a customer — so that a low price and a cheap mold stop being confused with each other.
A quotation that arrives as one lump sum tells you nothing. A quotation with six or seven lines tells you what you are buying. These are the cost blocks that make up the total, in the order they usually weigh on the final number.
| Cost block | Share of total | What it covers, and how it swings |
|---|---|---|
| Machining hours | 30 – 40 % | CNC roughing and finishing of cavity, core and inserts, plus EDM for ribs, deep pockets and sharp internal corners. Doubling the part surface area roughly doubles this line. |
| Mold steel & inserts | 12 – 22 % | From pre-hardened P20 through 718H, H13, 1.2344 to stainless S136. Going from P20 to hardened H13 for a glass-filled resin typically adds 15–25 % to material cost and forces more machining hours. |
| Mold base & standard components | 8 – 15 % | HASCO, DME or Meusburger base plates, leader pins, ejector system, springs, water fittings. A standard base is cheap and fast; a custom base adds weeks and cost for no functional gain. |
| Runner system | 5 – 20 % | Cold runner is the baseline. A hot runner adds the manifold, controller, nozzles and wiring — a real cost jump, justified only when scrap, cycle time or gate cosmetics pay it back. |
| Surface finish & texture | 3 – 12 % | SPI polish grades, chemical texture (VDI or MT), laser etching, hard chrome. A high-gloss A-surface is hand-polished and is priced by hours, not by area alone. |
| Design, Moldflow & sampling | 8 – 15 % | DFM report, 3D mold design, flow simulation, steel correction after T1, trial shots and dimensional report. Suppliers that skip this line are not cheaper; they are deferring the cost to your T1. |
Cavity count is the single biggest lever on price, and the least understood. Going from 1 cavity to 2 roughly multiplies the cavity-and-core work by 2 but leaves base, runner and design largely fixed — so the tool might cost 1.6x while halving your per-part cycle cost. Going to 8 or 16 cavities changes the economics again: the tool becomes expensive, but unit cost drops far enough that volume above roughly 100,000 pieces per year almost always justifies it.
The ranges below are for reference when sanity-checking a quotation. They assume a straightforward part without sliders, unscrewing cores or tight optical requirements, and they move with part size, tolerance and steel grade rather than with country of origin alone.
| Category | Typical part size | Cavities | Indicative tool cost (USD) | Lead time |
|---|---|---|---|---|
| Prototype / aluminum | up to 200 mm | 1 | 3,000 – 9,000 | 2 – 4 weeks |
| Small precision part | under 100 mm | 2 – 8 | 12,000 – 40,000 | 5 – 8 weeks |
| Mid-size enclosure | 150 – 400 mm | 1 – 2 | 18,000 – 55,000 | 6 – 10 weeks |
| High-cavity production | under 150 mm | 8 – 32 | 45,000 – 120,000 | 10 – 14 weeks |
| Large housing, hot runner | over 400 mm | 1 – 2 | 55,000 – 150,000+ | 10 – 16 weeks |
Most cost-down conversations start with asking the supplier for a discount. That rarely moves much, because the number is already built from hours and material. What does move it is changing the inputs on your side before the design is frozen.
When a quote lands 40 % under the others for the same drawing, the difference is usually not efficiency. It is one of these:
Comparing totals is the fastest way to buy the wrong mold. Normalise the offers first, then compare.
Three quotes normalised this way usually cluster within 15 % of each other. When one sits far outside the cluster, you now know which line it is, and you can ask the question instead of guessing.
Share the STEP file, the resin grade and your annual volume. We return a quotation split by cost block, with the steel grade, cavity count and expected shot life stated explicitly — so you can compare it against your other offers line by line.
info@j-mold.com
