After 27 years of quoting moulds — and re-quoting moulds that other factories failed to deliver — we can tell you the price gap almost always comes from the same five places. Only one of them is honest markup.
1. Steel grade — the biggest silent variable
A 400 kg household crate mould in P20 (1.2311) costs far less than the same mould in 718H (1.2738HH), and less again than H13 (1.2344). The difference in steel alone can be 15–30% of the tool price. Weak quotations simply don't state the steel — or state a brand name without a hardness certificate.
- P20 / 1.2311 — pre-hardened, fine for moderate volumes and non-abrasive resins
- 718H / 1.2738HH — higher hardness through the plate, standard for large household tools
- H13 / 1.2344 — for glass-filled resins and high annual volumes
- S136 / 1.2083 — stainless, for medical, optical and corrosive resins (PVC, flame-retardant grades)
What to demand: steel grade and a mill certificate with the delivery. We state both in every quotation.
2. Cooling design — where cycle time is won or lost
Cooling is 60–70% of the injection cycle. A mould with generous, well-placed cooling channels and beryllium-copper inserts in hot spots might cost 8% more to build — and run 20% faster for the next ten years. Quotes that skimp on cooling look cheaper and quietly cost you a fortune in piece price.
3. Cavity count — priced for your volume, not theirs
A single-cavity tool is cheaper to build and slower to run. A family tool costs more up front and slashes piece price. Which is right depends on your annual volume — not on what the supplier has spare capacity for. A good quotation states the assumed annual volume and cavity count explicitly, and offers the alternative.
4. Guaranteed cycle life — the warranty nobody reads
"Mould life 500,000 shots" means nothing unless it's written into the contract with a remedy. Ask each supplier to state the SPI mould class and what happens if the tool fails early. Our guarantee: Class 101 tooling rated 1,000,000+ shots; if a mould fails under normal use within the guaranteed count, we repair or replace the affected components free.
5. What's quietly excluded
The classic traps:
- "Price excludes trial samples" — T1 samples and express shipping billed later
- "Price excludes DFM / Moldflow analysis" — you find out the part warps after the steel is cut
- "Price excludes texture / SPI polish" — surfaces quoted as-delivered-machined
- "Price excludes packing and inland transport to port"
Our quotations itemise: tool design, Moldflow, steel with certificate, machining, hot-runner or cooling system, texture/polish spec, T1 trial with FAI report, wooden case packing and FOB Ningbo transport. Nothing billed twice.
The five-line comparison table to send every supplier
| Item | Ask them to state |
|---|---|
| Steel | Grade + hardness + mill certificate? |
| Cooling | Channel layout, Cu inserts in hot spots? |
| Cavities | Count + assumed annual volume |
| Life | SPI class + written remedy |
| Inclusions | DFM? Moldflow? T1 samples? Polish? Packing? |
Send this to all three suppliers and the "40% cheaper" quote usually collapses on its own. And if a supplier refuses to answer the table — that answers your question about them.
Want a quotation you can take apart line by line? Send us your part file — DFM opinion, tooling concept and a fully itemised price within 48 hours.