Quarterly Cost Index · Q3 2026

SunOn Manufacturing Cost Index Q3 2026: Real Data from the Factory Floor

The short version: if you're buying an injection mold or die-casting tool in Q3 2026, you have negotiating leverage you probably don't know about. Domestic Chinese mold steel fell as much as 15% this quarter while imported steel and machine-hour rates stayed flat. On the casting side, the aluminum-zinc price gap has nearly closed — die-casting aluminum ADC12 rose about 3% while zinc alloy dipped.

These are not analyst estimates. These are the prices my manufacturing group actually paid and quoted this quarter, published so hardware founders can check their supplier quotes against real numbers.

The numbers this quarter

Mold steel — what your tooling is made of

Steel gradeQ3 2026 pricevs Q2USD equivalent
P20, domestic¥5.9/kg↓ ~15%~$0.82/kg
718H, domestic¥14–18/kg↓ ~8%~$1.95–2.50/kg
S136, domestic¥25–32/kg↓ ~5%~$3.50–4.45/kg
ASSAB 718 (imported)¥35–45/kgflat~$4.85–6.25/kg
ASSAB S136 (imported)¥60–80/kgflat~$8.35–11.10/kg

Note the spread: domestic P20 now costs less than 1/6 of imported ASSAB S136. When your mold quote says "P20 steel," ask which tier — the price difference flows straight into your tooling cost.

Injection molding machine rates — flat this quarter

Press sizeQ3 2026 rateUSD equivalent
≤160T¥80–120/hour~$11–17/hr
160–400T¥120–300/hour~$17–42/hr
>400T¥300–500+/hour~$42–69+/hr

Die casting alloys — the interesting move

MaterialQ3 2026 pricevs Q2USD equivalent
Aluminum ADC12 ingot¥23,900–24,100/ton↑ ~3%~$3,320–3,350/ton
Zinc Zamak 3 ingot¥24,905–25,005/ton↓ ~1%~$3,460–3,470/ton
Zamak 3 processing fee¥600–700/tonflat~$83–97/ton
Zamak 5 processing fee¥1,300–1,400/tonflat~$180–195/ton

The trend that matters

Domestic mold steel is a buyer's market; everything else is sticky.

Chinese domestic tool steel has been sliding on overcapacity and soft domestic demand — P20 down roughly 15% in a single quarter is a big move for a material input. Meanwhile imported ASSAB grades didn't move (import pricing follows brand and logistics, not Chinese mill gates), and machine-hour rates didn't move (those are driven by labor and electricity, not steel).

On the casting side, a quiet crossover is underway: a ton of zinc alloy now costs roughly the same as a ton of die-casting aluminum (¥25.0K vs ¥24.0K). Two years ago zinc carried a clear premium. Aluminum's ~3% rise this quarter narrowed the gap further. Remember that aluminum is 2.5× lighter — so per part volume, aluminum's material cost advantage actually widened this quarter even as its ingot price rose.

One insider detail you won't find in any market report: Zamak 5 processing runs about double Zamak 3 (¥1,300–1,400 vs ¥600–700 per ton) at our operation. If your supplier quoted "zinc die casting" without specifying the alloy, that ambiguity is worth a question — Zamak 5's extra copper buys you hardness and creep resistance, but you pay for it twice: in the ingot and in the processing.

What this means for your project

If you're tooling this quarter: renegotiate the steel line item.

Steel is typically 15–25% of an injection mold's cost. A 15% drop in domestic P20 should show up as roughly a 2–4% reduction in a P20 mold quote versus last quarter — call it $800–1,600 on a $40,000 tool. That's not life-changing money. What matters more: a supplier who passes the reduction along without being asked is telling you something about how they'll handle the next 5 years of your relationship. A supplier holding Q2 steel prices in a Q3 quote is also telling you something.

The practical script: "I've seen domestic P20 pricing come down this quarter — can you walk me through the steel assumption in this quote?" You don't need to know the exact number. Asking the question changes the conversation.

How to use this data

FAQ

How much of a mold quote is steel?
Typically 15–25% for an injection mold, depending on size and cavity count. The rest is machining, EDM, polishing, fitting and margin. That's why a 15% steel drop translates to only a 2–4% mold price reduction — but on a $40K tool, that's still $800–1,600.
Why did domestic P20 fall 15% while imported ASSAB stayed flat?
Domestic Chinese tool steel pricing follows mill overcapacity and local demand, both soft this quarter. Imported steel pricing is set by brand positioning, import duties and logistics — it moves slowly and rarely follows Chinese domestic dips.
Should I switch from imported to domestic steel to save money?
Not on price alone. Imported grades like ASSAB S136 earn their premium in high-polish applications (optical parts, clear housings) and long production runs where mold life matters. For a 50K–500K unit consumer product with standard finishes, quality domestic 718H is often the right call. The decision is mold life and surface spec, not the steel invoice.
Does the aluminum price rise change whether I should choose aluminum or zinc?
Rarely. Alloy choice is driven by geometry (zinc casts thinner walls), operating temperature (aluminum handles >120°C better) and finish requirements. Material cost matters at high volumes, but a 3% ingot move doesn't flip a correct engineering decision.
Where does this data come from?
SunOn Manufacturer Group's own procurement and quoting records — mold making, injection molding and die casting operations in the Pearl River Delta. These are transaction prices, not survey estimates. Published quarterly. Next index: October 2026 (Q4).

Is your quote holding last quarter's prices?

Bring it to a free 15-minute call — I'll tell you what it should cost and why. Next index: October 2026.

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