How to qualify a new ADC12 supplier without stopping the line

Most foundries know they are over-exposed to one alloy supplier. Very few do anything about it, because the downside of a bad switch lands on the production floor and the upside lands on a spreadsheet in another department.

The way through is to stop treating it as a switch. Qualification is a parallel process that runs alongside normal production, and done properly it never puts a shipment at risk. Here is the sequence we see working across European die-casters.

Stage 1: Review the paperwork before you look at metal

Ask for a recent material test certificate from an actual heat, not a specification sheet. A specification sheet tells you what the alloy is allowed to be. A certificate tells you what it was.

Alongside it, request:

• The full composition report, including elements outside the EN AC-46000 list. Chromium and vanadium drive sludge and are not reported by default.
• The iron target and its spread. "Under 1.3%" is a limit. A supplier managing high-pressure die casting deliberately will name a band, typically 0.8 to 1.1%.
• CBAM embedded-emissions data. Mandatory for EU imports since January 2026. A supplier who cannot produce it on request will become your problem at declaration time.
• ISO 9001 certification and the EN 10204 certificate type they issue. 3.1 is the normal expectation.

This stage costs an email and filters out most of the field.

Stage 2: Order a trial quantity, not a container

Standard minimum order for ADC12 is 20 tonnes, one 20-foot container. That is too much metal to commit to an unproven supplier and more than you need to learn anything.

Ask for 5 to 10 tonnes. Any supplier serious about European business will do this for a first-time buyer, and a supplier who refuses has told you something useful. Five tonnes covers one or two production shifts on a representative tool, which is what you need.

Stage 3: Run it on a tool you already understand

This is where qualification programmes usually go wrong. The temptation is to try new metal on the part that has been causing trouble, on the theory that if it fixes that, it will fix anything.

Do the opposite. Run the trial on a tool with a well-characterised process window and recent baseline data, ideally a part you have been casting steadily for months. If you qualify new metal on a new tool or a problem part, you will not be able to separate the metal from the tooling, and you will end up with an inconclusive trial and an argument.

Change one variable. If the tool, the part and the process are all steady, anything that moves is the metal.

Stage 4: Measure the things that actually differ

Composition compliance is table stakes and the certificate already covers it. What you are testing is behaviour. Record these against your incumbent baseline over a comparable number of shots:

Trial measurements and what a change indicates

Measure	What it tells you
Misruns and cold shuts	Fluidity, which tracks silicon content and melt cleanliness
Die soldering and release behaviour	Iron level. Low iron solders; the effect shows within a shift
Porosity, by X-ray or sectioning	Hydrogen pickup and melt quality, influenced by calcium and sodium
Machined surface finish and hard spots	Intermetallic sludge from iron, manganese and chromium together
Furnace sludge accumulation	Residual element load; check the crucible after the trial, not during
Overall scrap rate	The number that decides the commercial case

Note the last row carefully. A metal that costs 3% more and cuts your scrap rate by a point is cheaper. Metal price per tonne is the number procurement is measured on and it is rarely the number that matters.

Stage 5: Run in parallel before you commit

A successful trial proves one delivery worked. It does not prove the supplier is consistent, and consistency is the thing you are actually buying.

Add the new supplier to the approved vendor list without removing the incumbent, and split volume for one to two production months. Watch heat-to-heat variation across several deliveries. This is where a refiner whose scrap intake changes month to month will show drift that a single trial container never would.

Once the second supplier holds steady across several deliveries, you can shift the majority of volume and keep the other as fallback. You now have supply security you did not have before, and a live price comparison that keeps both suppliers honest.

How long the whole thing takes

Typical qualification timeline

Stage	Elapsed time
Paperwork review and supplier shortlist	1 week
Trial order placed to delivery at EU port	10 to 30 days
Trial run and measurement	1 to 2 shifts, results within a week
Parallel running	1 to 2 production months
Total to a qualified second source	8 to 12 weeks

None of that requires stopping production, and none of it commits you to anything until stage 5. The only real cost is the attention of one process engineer for a couple of shifts.

The case for starting now

European primary aluminium supply is tight, CBAM has added a documentation burden that not every supplier outside the EU is equipped to carry, and single-sourcing an alloy that underpins your entire production is a risk that only becomes visible on the day it matters. Qualification takes eight to twelve weeks. It is worth starting before you need it.