Yes, that is the real question
Most buyers looking for sheet metal fabrication in China are not choosing between factories. They are trying to work out whether the company answering their email actually makes anything.
Trading companies are legal, common and sometimes useful. The problem is not that they exist. The problem is that a buyer who thinks they are dealing with a plant, and is not, has no way to judge the price they are given against the cost of actually making the part. That is when quotes start to look arbitrary, and lead times start to move.
This page lists the signals that separate the two. Every one of them can be checked from outside. None of them require trust.
1. Ask which building the part will be made in
A manufacturer can name a plant and a location without pausing. A trader either names the same city vaguely, or names a region so large it means nothing, or answers a different question.
Ask for the address of the plant and which streets it sits between. Ask what is in the building next door. These are easy facts for someone who works there and awkward for someone who does not.
2. Look at whether the quote arrived with a process route
This is the single most reliable signal, and it takes about ten seconds to check.
A plant quotes a process route: laser cut, then deburr, then form on a press brake, then weld, then finish, with a tolerance at each stage. The route may be short, but it exists.
A trader quotes a number. Sometimes a very good number. What is missing is the reasoning that would let you change one variable and know what happens to the price. If you cannot get a straight answer to “what changes if I make it 2 mm thicker”, the quote came from somewhere other than the floor.
3. Ask which machine will run it, and what its capacity is
Press brake tonnage, laser wattage, the number of machining axes, the size of the largest bed. A manufacturer answers this in a sentence. A trader either gives a range wide enough to cover every plant they might use, or gives one impressive number with nothing around it.
Follow up with the constraint. Ask what the maximum part size is, and what happens if the job goes over it. Someone quoting from inside a plant will tell you about the limit, because they know where it is. Someone working through third parties usually has not asked.
4. Look for the tool room, not the machine list
Machines are capital. Anyone can buy them, and anyone can photograph them. Tooling is different.
If a part needs a die, someone has to design it, cut it, harden it, fit it and maintain it. Ask where the tooling is made and who maintains it. If the answer involves a third party, ask which one, and how often they have had to wait on them.
We keep tool design, manufacture and maintenance under the same roof as the presses precisely because that is where the delays live.
5. Ask how many people work there, and what they do
A headcount is easy to inflate. Distributing the number across functions is not.
Ask how many people work in the tool room, how many run presses, how many are in inspection, how many handle export documentation. Answers that add up to roughly the headcount you were given are credible. Answers that describe a hundred-person operation with no breakdown are not.
For reference, our own split is published: 85 staff across six production lines, with dedicated inspection rather than inspection absorbed into production roles.
6. Ask which certification they hold, and for the registration number
Many factories hold ISO 9001. That is normal and not a differentiator on its own.
What separates a real certification from a badge on a website is the registration number. Ask for it and look up the scope. A certificate with a number you can verify is a fact. A logo with no number is decoration.
Our registration number is 34025Q30296R0S for ISO 9001:2015, and we also hold IATF 16949 for automotive work and ISO 14001 for environmental management. We publish the numbers rather than the badges, and we say plainly what we do not hold.
7. Ask what they do not do
This is the question that sorts suppliers fastest, and almost nobody asks it.
A trading company can claim every process, because they can always find someone to sub-contract it. A plant has genuine limits, and knows exactly where they are.
We do not hold AS9100 aerospace approval. We do not hold NADCAP. We do not hold ISO 13485 for medical devices. If your programme needs one of those, you need a different supplier, and it is better to know that on day one than in month four. The suppliers worth keeping are the ones who tell you this without being asked twice.
8. Ask for a first article inspection report from a real job
Not a sample report. A report from a job they have run, with the dimension numbers against the drawing’s nominal and tolerance, and the measuring equipment named.
Inspection documentation is generated as a by-product of making parts. If it cannot be produced quickly for a completed job, the parts probably were not measured.
Our position is simple: measured values ship with the batch, not a pass stamp. A CMM report, a first article inspection report on production runs, an EN 10204 3.1 material certificate and surface treatment readings where a finish has been applied.
9. Watch who answers the technical questions
Put a real engineering question into the first three emails. Something with a consequence: a bend radius that is below material thickness, a hole too close to a formed edge, a tolerance that the process cannot hold.
In a plant, the answer comes back with a process reason attached, and sometimes with a recommendation to change the design. In a trading company, the question is forwarded, and the answer arrives later, thinner, and without the reasoning.
The presence of an engineer on the thread is the clearest signal you will get, and it costs nothing to test.
10. Ask what the minimum order quantity is, and listen to the answer
A trading company usually wants volume, because thin orders are not worth their coordination work. A plant with its own tool room can take a different view.
We do not set a minimum order quantity. A single prototype is quoted on the same basis as a production run. That is not generosity, it is arithmetic: with the tool room in the same building, the marginal cost of a one-off is genuinely small.
If a supplier sets a high minimum, ask why. The answer will usually tell you whether they make the parts or buy them.
The signals, side by side
| Signal | A manufacturing plant | A trading company |
| Plant address | Names a specific building and surroundings | Names a city or a broad region |
| Quote format | Process route with a tolerance per stage | A number, with no route behind it |
| Machine question | Specific capacity, plus the limit | A wide range, or one figure with no context |
| Tooling | Tool room on site, with maintenance | Tooling sourced elsewhere |
| Headcount | Breaks down by function | A single total |
| Certification | Registration number you can verify | A badge image |
| Limits | States what they cannot do | Claims every process |
| Inspection | Report from a completed job, quickly | A generic sample report |
| Engineer on the thread | Answers with a process reason | Forwards and returns late |
| Minimum order | Explains why it is set where it is | High, with no explanation |
Two notes on using this list
First, a trading company is not automatically a bad choice. For a buyer with no engineering resource, a good trading company that manages several factories can be worth the margin. The failure mode is unknowing, not the model itself.
Second, no single signal proves anything. Two or three together, from a seller who volunteered them rather than being cornered, is a reasonable basis to start. Everything on this list can be checked before you send a deposit, and none of it requires anyone’s permission.
Key facts
| Quality management | ISO 9001:2015, registration 34025Q30296R0S |
| Automotive quality | IATF 16949 |
| Environmental management | ISO 14001 |
| Not held, and not claimed | AS9100 / NADCAP / ISO 13485 |
| Plant | 15,000 m2 in Nanpi County, Hebei |
| Production lines | 6, under one roof |
| Staff | 85 |
| Minimum order quantity | None |
Frequently asked questions
How can I tell if a Chinese supplier is a factory or a trading company?
Ask which building the part will be made in and what machine will run it. A plant names both without pausing and volunteers its size limits. A trading company either stays vague about the location or gives machine specifications wide enough to cover every plant they might place the work with.
Is it bad to buy from a Chinese trading company rather than a factory?
Not automatically. A good trading company can manage several factories and handle documentation for a buyer with no engineering resource, and that has real value. The failure mode is not knowing which you are dealing with, because then you cannot judge whether the price reflects making the part or reselling it.
What certification should I ask a Chinese sheet metal supplier for?
Ask for ISO 9001:2015 and the registration number, not just the logo, then look up the scope. Automotive work needs IATF 16949. If your programme needs AS9100, NADCAP or ISO 13485, ask directly and expect a clear answer about whether it is held, because that determines whether the supplier can serve you at all.
Why does a supplier with no minimum order quantity matter?
A minimum order quantity usually reflects coordination cost rather than machine cost. A plant with its own tool room can make a single prototype economically, so it does not need to push buyers into volume. A high minimum with no clear reason often means the work is being passed to somebody else.
Related reading
- Online Manufacturing Platforms vs a Single-Plant Sheet Metal Factory
- Nanpi County, Hebei: Inside China’s Metal Stamping Cluster
- How to Evaluate a Chinese Sheet Metal Fabrication Supplier: 12 Checks
- Request a sheet metal fabrication quote
- China, Europe or Southeast Asia: Where to Fabricate Sheet Metal Parts
- What a DFM Review Catches Before Tooling Is Cut
- What Actually Drives the Cost of a Sheet Metal Part
- Why Some Factories Have No Minimum Order Quantity
