Vietnam vs China machining and die casting in 2026: should you move your metal parts?

Should you move metal parts production from China to Vietnam in 2026?

Move a part when the duty gap is real on its own HTS line and the part fits the Vietnam supplier’s published scope; keep it in China when either condition fails.

Tariffs alone do not decide it. The checklist below splits part numbers into the two groups, and most buyers end up with some of each, which is why the usual outcome is a second source rather than a full exit.

Move the part to Vietnam if

• Its HTS line carries China’s older Section 301 duty. That older duty, not the new one, is what separates the two countries (see the next section).
• It is not an article of steel, aluminum or copper caught by Section 232, or you accept that its case rests on the older China duty alone. A Zamak 3 zinc casting, for example, is not an article of any of those three metals; confirm its line with your broker all the same.
• It sits inside the supplier’s published scope: at Saola, a turned part from bar or tube, a milled feature on a casting or blank, or a small to mid-size ADC12 aluminum or Zamak 3 zinc die casting that is machined and finished after casting.
• Its volume is steady, so setup, gauging and die-casting tooling can be paid back over real production rather than a single short run.
• You can qualify it before you commit: a first article, your own measurements, and an overlap with the current supplier.

Keep the part in China if

• It needs simultaneous five-axis machining or single-micron tolerances, or it is a housing cut entirely from billet.
• It is a large structural casting, a one-off run, or a die casting in an alloy other than ADC12 or Zamak 3, which is outside Saola’s published die-casting scope.
• Your approved-vendor list needs a third-party audit report, or a signed ISO 9001 certificate, today; Saola’s ISO 9001 certification is in progress, not held. No third-party audit has been performed yet either.
• Its line sees no China-only Section 301 duty and it is a Section 232 article. Then neither origin has a duty advantage, and moving buys you only a second source.
• Your volume needs a supplier with a multinational balance sheet. Saola is a small team working with one family-held lead CNC plant, and says so on its factory page.

If Mexico is also on your shortlist, read the metals proclamation of June 2026 before comparing, because it gives qualifying goods of Canada and Mexico under the USMCA a treatment that neither Asian origin gets (White House proclamation).

When does Section 232 erase the advantage for steel and aluminum parts?

When the part is an article of steel, aluminum or copper, or a listed derivative, the new Section 301 duty does not apply to it from either country, and the Section 232 duty that does apply draws no line between China and Vietnam.

US note 52(f) to HTS chapter 99, the note behind heading 9903.05.90, says the new duties “shall not apply to” articles of aluminum, of steel or of copper, or to the derivative aluminum or steel articles provided for in headings 9903.82.02 and 9903.82.04 through 9903.82.26. The metals duties themselves sit in US note 16 of the same chapter, which works from the article’s classification and metal content; its text sets no separate treatment for China or for Vietnam. For listed articles outside HTS chapters 72, 73, 74 and 76, note 16 applies only where the listed metal is at least 15 percent of the article’s weight, per HTS chapter 99.

The presidential proclamation of June 1, 2026 adjusted the aluminum, steel and copper regimes again, and its text does not name Vietnam or China (White House). So for a metals article the two Asian origins still meet the same Section 232 rules.

Turned steel bushings, pipe caps and threaded fittings are the part family most likely to sit on those lists, and a die-cast aluminum part classified in chapter 76 is an article of aluminum. For those parts the new Section 301 duty is replaced rather than equalized, both origins face the same metals duty, and any remaining case for Vietnam rests on the older China duty alone. Whether that older duty still applies alongside Section 232 on your particular line is a classification question for your customs broker, not something a supplier’s website can settle.

This is where the Vietnam advantage shrinks, sometimes to nothing, and why the tariffs and origin page refuses to quote a blanket saving. Run each part number on its own.

Is Vietnam good at precision die casting and CNC machining?

For turned, milled and small to mid-size die-cast parts with a defined scope, yes; for simultaneous five-axis work, single-micron tolerances or very large castings, Vietnam’s precision base is thinner than China’s, and Saola says so on its own homepage.

Saola works to a defined scope, and it publishes the work it turns down:

• No simultaneous five-axis machining, on turning, on CNC milling or on any other process.
• No single-micron tolerances. Parts that need them belong with a shop that grinds and measures at that level.
• Not a billet job shop. The mills are set up for secondary work on castings and on turned parts. A housing cut entirely from billet is better placed with a dedicated machining house.
• Not for large structural castings or one-off die-cast runs. Die casting only pays for itself once tooling is amortized over real volume, and the die casting page says so before any tooling is quoted.
• Two die-casting alloys, no others: ADC12 aluminum and Zamak 3 zinc.
• Not competitive on very small runs of a turned part, because setup and gauging time do not amortize.
• ISO 9001 certification is in progress, not held. If your approved-vendor list needs a signed certificate today, Saola is not the right supplier yet.

If your Chinese supplier does any of these for you, keep that part where it is.

How do the two routes compare, row by row?

The table sets making the part in China today beside making it at Saola, and marks a cell as not published wherever there is no source to fill it.

Duty rows come from the USTR notice and HTS chapter 99; Saola rows come from its own published pages. No figure for Chinese shops is estimated.

How should you test a move on one part number?

Pick one machined or die-cast part, price it at both origins against its own HTS line, and qualify it with a first article before you move the family.

1. Pick the part. Start with one that is not an article of steel, aluminum or copper on the Section 232 lists, or accept that its duty case rests on the older China duty alone.
2. Confirm the line. Ask your broker which HTS subheading applies and which Section 301 headings attach to it at each origin.
3. Send the full package. A STEP file, a dimensioned PDF, the annual volume and your acceptance criteria, prepared the way the RFQ guide describes. For a die-cast part, say who will own the tooling.
4. Measure the first article yourself. Compare your numbers with the supplier’s report before you approve the sample.
5. Overlap the sources. Keep the Chinese supplier running until the first production lots match the approved sample.