Most zinc die casting projects do not start with a new drawing. They start with a tool that already exists, sitting in another factory, and a buyer who has decided to move it. That is a different job from building a die from scratch, and it fails in different ways.
Here is the short version: transferring a die is usually faster and cheaper than cutting a new one, but only when the tool is mechanically sound and the receiving factory can actually fit it. If either condition is wrong, you will spend the savings on rework. Everything below is about telling those two cases apart before you commit.
What a tool transfer really involves
People say “transfer the mold” as if it were a shipping problem. It is a fitting problem. A die that ran happily in one plant has to be checked against a specific machine’s tie-bar spacing, platen size, die height, clamp stroke, ejector pattern and shot capacity. Get one of those wrong and the tool sits on the floor while everyone argues about whose fault it is.
At our plant the sequence is fairly fixed. Incoming inspection and a written tool condition report. Dimensional check against the original drawing, because drawings and tools drift apart over the years. Then a fitting trial on the machine we intend to run it on, dry cycling first. After that, water-line mapping, trial shots, a first article report, and only then a discussion about sampling and production.
The part most suppliers skip is the condition report. Ask for one in writing, with photographs of the cavity, core pins, slides and any heat checking. If a supplier is willing to receive your tool and give you an opinion on it before quoting, that is a useful signal about how they work.
What to send with the crate
The tool itself is maybe half of what the new supplier needs. These are the items that decide whether the first month goes smoothly:
- The original tool drawing, plus the part drawing at the revision actually being produced. Not the latest revision — the one the tool matches.
- Water-line and cooling-circuit diagrams, with flow rates if the previous plant recorded them.
- Previous process parameters: shot size, injection pressure, die temperature, cycle time. Even rough numbers save days of trial and error.
- A statement of what has been changed on the tool since it was built. Polishing, welding, insert replacement, gate rework. This is where surprises hide.
- The finish specification, including plating thickness and appearance standard. Moving the die does not move the polishing and plating process with it.
- Two or three parts from the last good production run. Physical samples settle arguments that drawings cannot.
If the previous supplier is uncooperative and none of this exists, the transfer can still work. It just becomes a reverse-engineering job, and you should price it that way.
Where transfers actually go wrong
Heat checking is the big one. A tool that has run a few hundred thousand shots has a network of fine cracks in the cavity surface. It still produces acceptable parts in the plant where it has always run, because everyone there has learned to polish around the problem. Move it, and the new plant’s first article report shows the cracks as surface defects, and the argument starts.
Cooling is the second. Scale builds up in water lines over years. The old plant compensates with longer cycle times and hotter dies without thinking about it. The new plant runs the book cycle time and gets porosity, short shots or warpage, and then spends two weeks blaming the tool.
Third is the gate. A die built for a 160 t machine may need a different gate configuration on a 250 t machine to keep the same fill pattern. That is real tool room work, not a setup adjustment, and it should be quoted up front rather than discovered at trial shot three.
None of these are exotic. They are predictable, which means they can be inspected for and priced before the tool leaves the original factory.
A realistic timeline
Four to eight weeks from crate arrival to parts you would be willing to ship is a fair expectation for a sound tool with complete documentation. Split roughly like this: one week for incoming inspection and condition reporting, one to two weeks for fitting, water lines and trial shots, one to two weeks for sample approval and any polishing or plating iteration, and the rest for first article documentation and production scheduling.
Add two to four weeks if the gate needs rework, if inserts have to be remade, or if the finish changes. Add more if documentation is missing and dimensions have to be rebuilt from the part.
Anyone who quotes a transfer in two weeks is either assuming your tool is perfect or planning to skip the inspection. Both are worth asking about directly.
When transferring is cheaper — and when it is not
A transfer makes sense when the tool has life left in it, the part is unchanged, and the volume does not justify a new die. It stops making sense in three situations: the cavity is cracked beyond polishing, the core pins and slides are worn past tolerance, or the part design has changed enough that the old gate and runner no longer fill it properly.
In those cases you are not transferring a tool, you are rebuilding one inside an old frame. The arithmetic usually favours a new die, because a rebuilt tool carries the old tool’s fatigue and gives you none of the warranty.
One more consideration that buyers in Europe and North America are weighing more heavily now: where the tool will live. A die that can run in either of two countries gives you options that a single-plant tool does not, and that flexibility is sometimes worth more than the transfer saving itself. We wrote about the commercial side of that in splitting zinc die casting orders between China and Vietnam.
How we handle it
STK has its own tool room, which matters here for a simple reason: the people who inspect your incoming die are the same people who can repair it. There is no round trip to a third-party tool shop and no gap in accountability between “the tool is fine” and “the parts are not”.
Hot chamber machines from 88 t to 400 t and cold chamber machines from 160 t to 1200 t cover most tools that arrive from Europe or North America, and the equipment list is published so you can check the fit before you ship anything. Inspection runs on CMM with first article and in-process reports under our ISO 9001:2015 system — details are on the quality control page.
Because both the Xiamen and Hanoi plants share the same tooling standards, a transferred die can be qualified in one location and, if duty or logistics change, run in the other. Finishing stays in-house: polishing, plating, PVD, powder coating and assembly all sit behind the same gate, which is usually where transferred projects lose the most time.
Questions buyers ask us
Can you transfer a tool without the original tool drawing?
Yes, but the first step becomes measuring the part and reconstructing the die geometry, and that work has to be paid for. It also shifts risk: without the drawing, nobody can prove whether a dimension was always like that or changed in transit.
Who pays if the tool is damaged in shipping?
Whoever arranged the freight and insurance, which is why the Incoterm on a tool shipment deserves as much attention as the one on production parts. Photograph the crate and the tool before it is opened, in front of the carrier’s representative if possible.
Does a transferred tool need a new PPAP?
In practice, yes. A new manufacturing location, new machine and new process parameters mean new evidence. Buyers who accept a transferred tool on the old PPAP are accepting risk they usually do not intend to accept.
How much does a transfer cost compared with a new die?
There is no honest single number, because it depends on the condition of the tool. Ask for the condition report first, then a quote for the transfer, then a quote for a new die. Comparing those three documents tells you more than any percentage anyone quotes you up front.
If you have a tool sitting idle and a drawing that matches it, send us the tool drawing, the part drawing and a few photos of the cavity. We will tell you honestly whether it is worth moving — contact STK. For the wider picture on tooling, our practical guide to die cast tooling and the mold making service page cover design, materials and maintenance.