Sourcing CNC Machined Parts From Vietnam, Step by Step
Moving a machined part to a new country is mostly a filtering problem. The machining itself is standard work. What goes wrong is picking the wrong part to move, writing a request nobody can quote, and comparing numbers that were never comparable. Here is the order to do it in.
Step 1: pick the right part to move first
Not every part in your bill of materials is a sensible first candidate. Good first parts share a few traits.
- The drawing is stable. You are not going to revise it next month.
- The quantity is real. A shop quotes differently for 5 pieces and for 500.
- The material is common. Aluminium, stainless, mild steel, brass and standard engineering plastics are bought locally. An alloy that has to be imported adds cost and weeks before a chip is cut.
- The tolerance is honest. A drawing with ±0.01 mm on every dimension because that is what the template said will be quoted as if you meant it.
- Nothing is export controlled. Defence, ITAR and dual use parts are a different process and do not belong in a first sourcing exercise.
Bad first candidates are the opposite: a new design under a launch deadline, a single prototype, or a part whose material you cannot name.
Step 2: write an RFQ a shop can price without guessing
Most slow quotes are not the shop being slow. They are the shop waiting for an answer. A request that can be priced on the spot contains:
- A STEP file, or a PDF drawing with dimensions on it
- A note on which features are critical and which are general
- Material and temper, or the words “or equivalent” if a substitute is acceptable
- Surface finish, and any coating or plating with its specification
- Quantity now, and what you expect to use in a year
- The date you need parts in hand, not the date you would like them
- The destination country and whether you want a price to the port or to your door
- Any inspection documents that must travel with the shipment
The last two matter more than first time buyers expect. A quote to the shop door and a quote to your warehouse are different numbers for the same part, and which shipping term you ask for decides how much freight and duty sits inside the price.
The full RFQ guide has a template you can copy, along with the reason each field changes the price.
Step 3: ask a small number of shops, not a long list
Sending one drawing to twenty shops feels efficient and is not. Shops triage. A request that arrives with nineteen other names on it gets a fast, high, safe number, or no number at all. Three shops that were chosen because they run your process, your material and your part size will beat twenty that were chosen because they had a website.
If you are doing the filtering yourself, the questions worth asking before you send the drawing are: what machines do you run, what is your largest part envelope, which materials do you buy locally, do you quote in English and have you exported directly before. The vetting checklist goes through what evidence to ask for behind each of those answers.
Step 4: compare the quotes properly
Line the quotes up on the same terms before you look at the totals.
| Check | Why it matters |
|---|---|
| Same Incoterm | An EXW price and a DAP price are not comparable |
| Same quantity | Some shops quote a different break to make the number look better |
| Tooling and fixture cost | Sometimes separate, sometimes buried in the unit price |
| Lead time from purchase order | Not from the day material arrives |
| What is excluded | Export packing, pallets, inspection reports |
| Payment terms | A deposit is normal on a first order |
The cheapest unit price with a missing fixture line and a three week material lead is often the most expensive quote in the set. Once the scope is level, convert each quote into a landed cost per part so a number from Vietnam and a number from anywhere else sit on the same line.
Step 5: place a first order you can afford to lose
Treat the first order as an audit you are paying for rather than a purchase. Order the part you chose in step 1, at a quantity you can absorb if it slips, and ask for a first article inspection before the full batch runs. That one step catches most of what goes wrong: a misread tolerance, a wrong finish, a datum interpreted differently to how you drew it.
Keep the communication in writing. Confirm the revision number of the drawing in the purchase order. Ask the shop to send photos of the parts before packing, not after.
How long the whole thing takes
Buyers plan the machining and forget the rest, then find the first order took twice as long as the quote said. A realistic first cycle looks like this:
| Stage | Who controls it |
|---|---|
| Writing the RFQ and answering questions | You |
| Quoting | The shops |
| Purchase order and deposit | You |
| Material purchase | The shop, unless you allowed an equivalent grade |
| Programming, fixturing and machining | The shop |
| Secondary processes such as plating or heat treatment | A subcontractor nobody can call |
| First article, and your approval of it | Mostly you |
| Export packing, documents and freight | Shared |
Three of those eight stages are substantially yours. A complete RFQ, an “or equivalent” on the material and a named person who approves the first article within two working days will usually take more elapsed days out of a first order than anything the shop can do. The lead time breakdown goes through each stage in turn.
Step 6: decide what to do with the relationship
After one clean order you have something worth more than the price: a shop that has proven it can read your drawings. That is when to talk about the next parts, annual volumes and a stocking agreement. It is also when to keep your existing supplier rather than drop it. A second source is the point, and the sequence for running two in parallel without breaking the first is in the second source playbook.
If you want the filtering done for you, send the drawing and we will pass it to up to three shops in Vietnam that already run that material and quantity. You deal with them directly from the first reply.
Frequently asked questions
Do I need an agent to buy machined parts from Vietnam?
No. Plenty of buyers work directly with a shop once they have found one. The work an agent saves you is the finding and the filtering, not the buying. Once you have a shop that quotes well and delivers, you can run the relationship yourself.
What is a realistic first order?
Something you already buy, at a quantity where a mistake is survivable. A repeat part with a stable drawing and a few weeks of stock behind it is a better first order than a new design with a launch date attached to it.
Should I visit the shop before ordering?
For a first small order, usually not. For a part that carries real risk, or before you move an annual volume, a visit or a paid third party audit is worth the cost. You can also ask for photos of the machine your part will run on and of the inspection equipment.
Need a quote for a part like this?
Send the drawing. We shortlist up to 3 machine shops in Vietnam, manage the order if you want us to and reply within 24 business hours.
Send my RFQ