The lowest China die casting quote is usually the most expensive outcome, because a cheap number assumed a lighter die, a shorter tool life or tolerances the drawing never stated. Choose a factory, not a trading desk: you should be able to name the machine tonnage, walk the tool room on video, and receive a written DFM report before steel is cut. Require tooling ownership in writing, compare landed cost per good part across the program, and send the same STEP-plus-drawing package to every bidder so you are not comparing different assumed tools. English-speaking engineers on the enquiry, ISO 9001 on the wall, and a willingness to tell you to machine a low-volume part are stronger signals than a polished catalogue.
Sourcing aluminum die casting in China is not hard. Sourcing a program that still looks cheap in year three is. The difference is rarely the country. It is whether you awarded a factory a complete tool, or awarded a mailbox a hopeful number.
This is the checklist we would use if we were the buyer.
Start with the factory test
You are buying machine time, steel and process control. Those live in a building.
Ask for all four. A real factory answers in the first reply.
- Machine list. Cold-chamber tonnage, not “we have many machines.” Aluminum needs cold chamber. A zinc-only shop will still say yes.
- Tool room. CNC, wire EDM, sinker EDM, grinding. If tooling is “our partner,” you have two vendors and one argument when T1 is late.
- Live video. Not a rendered tour. The cell, the die on the bench, the CMM. Time-zone math is inconvenient; that is the point.
- Who reads the drawing. The person who replies should open the model. If every technical question is “I will check with the factory,” you are talking to a trader.
CharMax manufactures in Qingxi, Dongguan. The company page lists cells, alloys and what sits in the same building. We expect you to ask the same questions of everyone else.
Demand tooling terms in writing
The die is the largest asset you will put in someone else’s plant.
| Term | What to require |
|---|---|
| Ownership | Title transfers when the tool is paid. The die is yours. |
| Exclusivity | Never used for another customer, never copied for stock parts. |
| Storage | Factory stores and maintains it; rust and idle-die care are their job. |
| Exit | You can move or ship the die on written notice. Spell the notice period. |
| Amortisation | If you amortise, define what happens if volume never reaches the quantity. |
| Modifications | Who pays for T1 changes, and how insert replacement is priced. |
If those lines are missing, the cheap tooling quote is not cheap. It is unfinished. The tooling cost article explains what a complete quote contains.
Compare programs, not unit prices
A die casting quote is a set of assumptions. Align them before you rank suppliers.
| Line | Why it changes the real cost |
|---|---|
| Cavity count and slides | Different tools, different piece prices |
| Expected shots | A 40,000-shot die on a 200,000-shot program is a second tool |
| Machining scope | Sealing faces and threads often exceed casting conversion |
| Finish specification | “Powder coat” and a named powder, thickness and visible faces are not the same |
| Inspection | 100% criticals vs sampling changes both price and risk |
| Incoterms and packing | EXW plus your freight forwarder vs FOB Shenzhen is not a $0.40 difference |
| T1 loop | How many sample iterations are included |
Landed cost per good part over three years is the ranking number. Incoming rejects, tooling corrections and engineering hours belong in that number even if they never appear on the PI.
Send one RFQ package
Different packages produce different assumed tools. Then you think you ran a tender.
Send every bidder the same files:
- STEP (AP214 or AP242).
- 2D PDF with datums, critical balloons, cosmetic zones and general as-cast tolerance.
- Alloy, or “recommend and justify.”
- Finish, with visible vs hidden faces.
- Annual volume and three-year outlook, separately.
- First release quantity.
- Whether draft is already applied.
- Target markets or any material restrictions (RoHS, specific secondary alloys).
The CAD checklist is the submission standard we use on inbound RFQs. Use it outbound.
Questions that expose a weak supplier
Ask these after the first quote, not in the brochure stage.
- Where would this part run? Machine tonnage and why. A 1,250-ton answer on a 180 g cover is a copied sentence.
- Which features need slides? If they missed an undercut you can see, they did not open the model.
- What would you change in DFM? A factory names wall steps, sharp corners and parting-line clashes. A desk says “no problem.”
- When is die casting the wrong process? If they never say “machine this,” they will sell tooling into a 400-piece year.
- How do you control porosity on this geometry? Overflows, vacuum, alloy choice, or X-ray — specific to the thick sections on your part.
- Can I speak to the process engineer after PO? You will need that person at T1.
Certifications: use what is real
ISO 9001:2015 is a reasonable baseline for industrial OEM work. Material certificates, FAI, and PPAP on request are reasonable commercial extras.
Do not treat marketplace badges as process capability. Do not require IATF 16949 or ISO 13485 from a shop that does not hold them; you will either be shown a borrowed certificate or you will filter out honest factories. If your customer requires those systems, say so early and only shortlist plants that can show the current certificate.
Our quality page states what we hold and what we document. Ask every bidder for the same two pages: certificate and the inspection plan for your part.
Working cadence that keeps a China program sane
- One English-speaking engineer as the day-to-day contact, not a rotating chat ID.
- Written DFM before steel is cut. Photographs are not a report.
- T1 with a dimensional report against the drawing, not “samples look good.”
- A single owner for casting and machining if both are required. Split vendors split the tolerance stack.
- WhatsApp or email with file names and revision letters. Verbal ECOs become the wrong die.
Time zone is not the risk. Unowned decisions are the risk.
A scoring card you can reuse
Score each bidder 1–5. Weight the first three twice.
| Criterion | 1 | 5 |
|---|---|---|
| Factory evidence | Brochure, no video | Live cell + named tonnage |
| DFM quality | “OK to tool” | Written changes with reasons |
| Tooling terms | Vague ownership | Title, exclusivity, exit |
| Quote completeness | Piece price only | Tool spec, machining, finish, freight |
| Honesty on volume | Always “yes, cast it” | Will recommend CNC when volume is low |
| Communication | Translator relay | Engineer opens the model |
Award the highest weighted score, not the lowest piece price. If two factories are close, visit or run a paid T0 / machining trial on the harder part.
If you want that process run on your drawing, send the same package to us. You will get a DFM note and a cavity-count recommendation even when the recommendation is “do not tool this yet.”
