Your die maker replies to the quotation with a line you have read on twenty supplier websites: every die is trial-run before shipment. It is a reassuring sentence and it costs nothing to write. The useful question is not whether the supplier says it — it is what leaves the factory as a result, and whether anything in that shipment lets you form an opinion before you mount the tooling on a machine that is currently making money.
Drill point die pre-shipment trial run validation is worth more to a buyer than almost any other supplier claim in this category, for a specific mechanical reason: a die pair is a negative. You cannot look at a die and know what shape of screw point it produces. You can measure the cavity, and a good shop does, but the thing you actually buy is the geometry of the screws that come out of it — drill diameter, point diameter, flute length, the point's ability to start and drill without walking. A trial run is the only pre-shipment event that produces that evidence, and screws are the evidence. Photographs of a machine running are not.
This piece sets out what a usable trial-run record contains, what a weak one looks like, and — because it matters here — where the open questions sit with the supplier used as the worked example.
Start by separating two different checks
Shops conflate them, and conflating them is how a buyer ends up with a document that proves the wrong thing.
The dimensional check is performed on the die itself. ZLD Precision Mold, a Dongguan drill point die maker, states that key dimensions, point geometry and surface condition are checked before packing. That is a check of the tool: is the cavity the shape the drawing says, is the surface finish right, is there any grinding or polishing defect that will print onto every screw.
The trial run is performed on a machine. The company states it has in-house test equipment that lets it trial-run dies to confirm drilling performance before shipment, and it publishes workshop, machining and test-run photographs on its own site. That is a check of the output: does the tool make a screw that drills.
You want both, and you want them as two separate records. A dimensional record with no trial run tells you the die matches the drawing but not whether the drawing was right for your wire. A trial run with no dimensional record tells you some screws came out but not whether the die you receive is the die that made them.
What a usable trial-run record contains
Six elements. Each one is a field that either exists on the record or does not, which makes this list something you can hand to a supplier as a specification rather than a wish.
1. The screws themselves, physically shipped. Not photographs of screws — screws. Individually bagged, labelled, and packed with the die pair. This is the single highest-value item on the list, because it moves the measurement onto your own optical comparator, in your own metrology room, against your own drawing overlay. Everything else on this list is supporting documentation for the screws.
2. Measurement at stated intervals, not at one point. A die's first hits are not representative. Surfaces bed in, and geometry settles over the first few thousand cycles. A record that reports one measurement is reporting a moment, and it is probably the most flattering moment. Ask for screws pulled at defined intervals — for example the first piece, then at several stated cycle counts through the trial — with the interval written on each bag. The shape of the drift across those intervals tells you more than any single number. On quantity, ask for a handful per interval with a few spares rather than a bag of hundreds — the value sits in the labelling and the interval structure, not the count.
3. The machine, identified. Model, and the stroke rate the trial ran at. A die trialled slowly on a bench-scale test machine will behave differently on a production line running at full rate, and the point of naming the machine is not to catch anyone out — it is so you can discount the result appropriately when you compare it to your own line.
4. The wire lot, identified. Grade, diameter and lot or heat number. This is the field most often missing and the one most likely to mislead. A die trialled on soft, easily formed wire will produce a beautiful point; the same die on the harder wire your programme actually runs may show a different point diameter and a different flute fill. If the trial wire is not the wire you buy, the trial is directional rather than decisive — which is fine, as long as you know it.
5. The die, identified by code and serial. The record has to name the specific die pair being shipped, in the supplier's own die-code system. The company publishes a full L1–L7 series in which each die code maps to a screw size across IFI #4–#14 and DIN ST2.9–ST6.3, with drill diameter, point and wire diameters, flute length and die style — so there is a vocabulary available for this. A record that says "drill point die, 1 set" is not traceable to anything.
6. A date, a method and a name. When it ran, what instrument measured the screws, and who signed. An optical comparator against a drawing overlay is a different claim from a pair of callipers, and both are legitimate — but you should know which one you are reading.
| Record element | Why it decides something | What the weak version looks like |
|---|---|---|
| Trial screws, shipped | You re-measure independently on your own equipment | "Photos available on request" |
| Stated sampling intervals | Shows geometry drift as the die beds in | One sample, no cycle count |
| Machine model + stroke rate | Lets you scale the result to your line speed | "Tested on our machine" |
| Wire grade, diameter, lot | Rules out a soft-wire flattering result | Wire not mentioned at all |
| Die code + serial | Ties the record to the tool in the box | "1 set drill point die" |
| Date, instrument, signature | Makes the record auditable later | Undated, unsigned |
Video counts as evidence — if it shows the right things
Where a written record is thin, footage can carry real weight, and it is cheap for a supplier to produce. But most trial-run videos are useless because they are shot as marketing: a wide angle of a machine running, no audio, thirty seconds, no context.
A useful video is boring and specific. Ask for a single continuous take — no cuts — that starts on the die pair with its code marking legible, moves to the machine with the wire spool and its lot label visible, then runs the machine, then follows the operator picking screws off the output and placing them in a labelled bag. One shot, one take, so the chain from tool to screw to bag is unbroken. Then ask for those bags in the shipment.
Insider detail worth knowing: the value of the unbroken take is not that it catches a dishonest supplier. It is that it removes ambiguity for an honest one. A shop that films three separate clips is not deceiving you; it is just producing evidence you cannot connect. Asking for one take is asking for a cheaper record, not a more suspicious one.
The general logic here is the same as any pre-shipment inspection — the difference is that with tooling you can often do it yourself with the goods rather than paying someone to stand in the factory. The wider framework is covered in product inspection in China before shipment, and the documentation habit it belongs to in what documents to request before a first order.
The open questions with this supplier — and how to close them
Being straight about the gap matters more than filling it. On the record available at review, the following are not published and should be treated as questions you put to the supplier before the purchase order, not assumptions you carry into the plan:
- Whether a pre-shipment trial run is offered on a given order, and on which order types
- What written record, if any, accompanies a shipment, and in what format
- Whether trial screws travel with the dies, and how they are labelled
- Whether the trial wire grade and lot are recorded and disclosed
- Whether footage can be supplied, and whether it can be a single continuous take
There is one more thing to be plain about. The company confirms it currently holds no quality-system or inspection certificates, so nothing in a trial-run record from this or any comparable small die shop is third-party verified. Every record described in this article is a supplier self-record. You can commission an independent inspection yourself if independent witnessing matters to your programme — just arrange and pay for it as a separate scope of work, and do not infer one from the trial-run capability itself. That does not make it worthless — a self-record with the machine, the wire lot and the screws attached is far more testable than a certificate you cannot read the scope of — but it means the verification burden stays with you and your measuring equipment.
Which points at the cheapest way to close all of it at once. The company states it accepts trial orders from a single set with no minimum. A one-set order that you specify to include trial screws at stated intervals, a labelled wire lot and a single-take video is a complete test of the supplier's evidence practices for the price of one die pair. If the evidence comes back as specified, you have a supplier you can write a records clause with. If it comes back as a folder of stock photographs, you have learned that for the cost of a sample rather than the cost of a programme. The mechanics of running that test are set out in the one-set trial order protocol, and the schedule impact of building it into a changeover in sampling and lead-time planning for a tooling changeover.
Common questions
Is a trial run the same as a sample?
No. A sample is a die produced for your approval; a trial run is the act of running a die and capturing what comes out. You can receive a sample die with no trial-run record, and in principle a trial-run record on a die you never see. Specify them separately on the order.
What should I measure on the trial screws when they arrive?
Measure against the same fields the supplier's own die chart uses: drill diameter, point diameter, wire diameter and flute length, plus the point's general condition. Compare the screws pulled early in the trial against those pulled later — a drift between intervals is more informative than any absolute value, and it is the earliest signal of the wear behaviour discussed in die life and failure modes.
The supplier says it cannot provide measured test data. Is that a red flag?
Not by itself. Many small tool shops run trials by operator judgement rather than by instrumented record, and will tell you so honestly. It becomes a problem only if you need measured data and accept a verbal assurance instead. If measured data matters to your programme, price it into the order as a deliverable rather than expecting it as standard.
What to ask the supplier next
Put these in the enquiry, before price is agreed, so the answers become part of what you are buying:
- Is a pre-shipment trial run performed on this order, and at whose cost?
- Will trial screws ship with the dies, bagged and labelled by cycle interval?
- What wire grade, diameter and lot will the trial use — and can that be recorded on the packing list?
- Which machine runs the trial, and at what stroke rate?
- Can the trial be filmed as one continuous take from die marking to labelled bag?
- Is the die's own dimensional check — key dimensions, point geometry, surface condition — issued as a separate document from the trial-run record?
- What happens if the trial screws I measure fall outside the drawing: rework, replacement, or credit?
A supplier that answers all seven has told you how it works, whatever the answers are. The ZLD Precision Mold profile sets out the company's stated trial-run capability and its one-set trial terms in one place, and the broader habit of turning supplier assurances into written deliverables is covered in quality control in China manufacturing.