GB/T 14486-2008 Tolerance Table — Updated October 2026

Update (October 2026): GB/T 14486-2008 was withdrawn on 28 March 2025. Its replacement is GB/T 47067-2026, which came into effect on 1 August 2026 and modifies/adopts ISO 20457:2018. The tolerance values below remain valid as a reference for legacy drawings, but new drawings should specify GB/T 47067-2026 or ISO 20457:2018. This page has been revised accordingly.

Plastic injection molding tolerance standard GB/T 14486-2008

GB/T 14486-2008 is a Chinese national standard for dimensional tolerances of plastics moulded parts. Different countries use different standards for their injection molded parts, and although the accuracy levels are broadly similar, they are generally not interchangeable.

That is why TONGDA LINK manufactures molds and runs molding to the standard stated on the customer’s 2D drawing — whether that is GB/T, DIN, ISO, or the customer’s own specification. We do not convert standards on our own side. If your drawing says MT3, we work to MT3.

⚠️ Important: GB/T 14486-2008 has been withdrawn

The standard was withdrawn on 28 March 2025. Its successor, GB/T 47067-2026, took effect on 1 August 2026.

What this means in practice:

Existing drawings marked GB/T 14486-2008 are still workable — the numbers don’t disappear, and we will manufacture to them. But they reference a retired document, which can cause problems in audits, PPAP/FAI documentation and contractual disputes.

New drawings should cite GB/T 47067-2026 (for Chinese-national-standard drawings) or ISO 20457:2018 (for international drawings).

GB/T 47067-2026 modifies and adopts ISO 20457:2018. So the Chinese national standard has now converged with the international one — which makes cross-border quoting simpler than it used to be.

DIN 16901 note: If you are a European buyer you may know this family as DIN 16901. That standard was withdrawn years ago and replaced via DIN 16742:2013 by DIN ISO 20457. It should now be cited only as a historical reference.

One correction we owe you: what ISO 20457 actually covers

ISO 20457 is often misdescribed — including, previously, on this site — as a standard for mould tolerances. That is wrong.

Its full title is ISO 20457: Plastics moulded parts — Tolerances and acceptance conditions. It governs the moulded part, not the mould. Mould accuracy is a separate matter, handled by mould-base standards and the toolmaker’s own specification.

This distinction matters at FAI. When a supplier says “we work to ISO 20457,” they are telling you how the part will be judged, not how precisely the cavity was machined. Those are two different conversations.

Key point 1: GB/T 14486-2008 was derived from DIN 16901:1982 (not equivalent adoption). They’re parent and child, not rivals. The Chinese standard’s own foreword records the differences: 28 size steps versus 21. In the small-size range the values are close; in larger sizes GB/T’s tolerances are tighter — roughly half a grade finer. That alone explains why the same dimension can pass under one standard and fail under the other.

Key point 2: ISO 20457 is DIN 16901’s true successor. Germany’s line runs DIN 16901:1982 → DIN 16742:2013 → DIN ISO 20457:2021-06. They ended up adopting ISO 20457 directly.

Key point 3: GB/T 47067-2026 modifies and adopts ISO 20457:2018. So the Chinese national standard has effectively converged with the international one. If you work to ISO 20457 and your supplier works to GB/T 47067, you’re now speaking nearly the same language — which wasn’t true before.

Three things in ISO 20457 / GB/T 47067-2026 that change how you write a drawing

1. Grades come from points, not just a lookup table

GB/T 14486: pick material + grade, read the number. ISO 20457 uses a points-based method combining nominal size, material shrinkage, geometric complexity, mould structure and functional requirement, then maps the total to TG1…TG9. It forces you to decide why a dimension matters before assigning a tolerance.

2. W dimensions vs. NW dimensions

W (werkzeugbezogen): defined within a single cavity/core — tighter.
NW (nicht werkzeugbezogen): affected by parting-line offset, mould wear or ejection deformation — looser.

This is the formal version of the “b class” idea in GB/T 14486. Marking W/NW on the drawing removes ambiguity at source.

3. Acceptance conditions are written into the standard

ISO 20457 specifies the measurement environment (23 ± 2 °C), conditioning time after moulding (typically 16–72 h depending on material), how the datum system is established, and the conformity decision rule together with ISO 14253-1 (accounting for measurement uncertainty).

Which means: a tolerance without stated measurement conditions is not verifiable. A number alone proves nothing.

Is there an MT → TG conversion table?

No, and anyone who gives you one is guessing. MT comes from a material-and-size lookup; TG comes from a points total that includes geometry, mould layout and function. There is no one-to-one mapping.

What works: take each critical dimension individually, classify it as W or NW, check it against the material’s shrinkage behaviour, and agree the grade before tooling starts. Slower than a conversion chart. Also the only method that doesn’t produce surprises at T1.

What to put on your drawing now

• International drawings: ISO 20457:2018, with grade per dimension and W/NW where relevant.
• Chinese-national-standard drawings: GB/T 47067-2026, not GB/T 14486-2008.
• Always state: measurement temperature, conditioning time, datum references, and whether the tolerance applies to the as-moulded condition or after secondary operations.
• DIN 16901: historical reference only.

And when comparing quotes, make sure all suppliers are quoting to the same document. A “tighter” number means nothing if it is measured under looser conditions.

[±0.005mm Tolerance in Plastic Molding: A Practical Guide]

— where sub-0.01mm is actually achievable on plastic parts, and what evidence to ask for (CMM reports, Cpk, machine MPE).

[Tolerance Capability Sheet]

— realistic tolerance bands by material and feature size, plus our verification practice.