Avoiding Miscommunication with a Vietnamese Fabricator: Drawing Notes, Units and RFQ Language

Most quality problems on a first overseas order are not welding problems. They are reading problems: a note the shop understood differently than the buyer meant, a tolerance written in a convention the shop does not use by default, an email thread where “yes, understood” meant “yes, I read your message” rather than “yes, I agree.” None of this is unique to Vietnam, but it is worth naming plainly because a buyer who expects it writes a better drawing and a better email, and gets a better part.

English is a second language for the engineer, not a barrier to competence

Vietnamese fabrication shops that export regularly work in English daily, and the engineers reading your drawing are competent at their trade. The gap is not ability, it is idiom. A note that says “as required” or “typical unless noted” leans on English legal and drafting convention that a non-native reader may parse literally rather than idiomatically. Plain, direct language beats formal drafting language every time: “grind flush” reads better than “dress to blend,” and a specific number beats a qualitative word almost always.

Units and conventions that quietly cause errors

• Decimal points and thousands separators. Some conventions use a comma where others use a period. “12,5” and “12.5” are not interchangeable, and a drawing exported from a CAD system with the wrong regional setting can silently swap them. Check dimension values against a rendered PDF, not just the CAD file, before sending.
• Metric by default. Vietnamese shops work in metric. An imperial drawing is usually converted, and every conversion is a chance to round wrong. If the original design is imperial, say so on the drawing and give the exact imperial value alongside the metric conversion for critical dimensions, so the shop can check rather than trust the conversion.
• Date format. Day-month-year is standard in Vietnam and much of the world; month-day-year is standard in the US. A delivery date written as 03/04 is read two different ways depending on who is reading it. Spell the month: “3 April 2027.”
• Surface finish and tolerance symbols. ISO and ASME both use GD&T symbols, but the exact interpretation of a datum callout or a surface finish symbol can differ subtly between the two systems. If your drawing was drafted to ASME Y14.5 and the shop defaults to ISO 1101, say which standard governs, in writing, on the drawing itself.

What belongs in the RFQ, in plain words

An RFQ that reads well in translation states, rather than implies:

• The governing drafting standard (ASME or ISO), named explicitly.
• Every critical tolerance as a number, not a qualitative word like “tight” or “as needed.”
• Units for every dimension, even where the drawing default should make it obvious.
• The delivery date written with the month spelled out.
• Photographs or a rendered isometric view alongside the 2D drawing, for anything with a complex geometry, because a picture removes an entire category of misreading.

Where verbal confirmation fails and written confirmation works

A phone or video call is useful for building trust and asking open questions, but a specification agreed verbally and never written down invites two different memories of what was agreed. The practice that works: after any call where a technical point is settled, send a one-paragraph email summarizing exactly what was agreed, and ask for a one-line reply confirming it. That reply, not the call, is the record everyone works from.

Silence is not agreement. “Understood” in a reply to a long email sometimes means the whole email was read and accepted, and sometimes means only the last sentence was. Ask direct yes/no questions for anything that matters: “Can you hold 0.05 mm flatness across this face, yes or no?” gets a clearer answer than “Please review the attached tolerances.”

Why this matters more on a first order

A shop and a buyer who have worked together for two years develop a shared shorthand: they know which notes the other side reads literally and which they read with judgment. A first order has none of that shared history, which is exactly why the drawing and the RFQ have to carry more explicit information than they would on a repeat order. The RFQ spec template is built around this: it forces the specific values into the request instead of leaving them to be inferred.

How this fits the matching model

Part of what a matching service should do is catch an ambiguous drawing before it reaches a shop, not after a part comes back wrong. When a drawing note is unclear, we ask rather than guess, and we write the clarification back into the RFQ so every matched shop quotes against the same understood scope. Send your drawing through the RFQ form and if anything on it reads as ambiguous, expect a question back before it goes anywhere, within 24 business hours.