Table Pdf — Iso 20457 Tolerance

Below is a representative example of the tolerance table structure from ISO 20457 (values in mm, for general-purpose unfilled plastics):

| Nominal dimension (mm) | Tolerance grade 1 (fine) | Grade 2 (medium) | Grade 3 (coarse) | Grade 4 (very coarse) | |------------------------|--------------------------|------------------|------------------|------------------------| | 0 – 3 | ±0.05 | ±0.10 | ±0.20 | ±0.40 | | >3 – 6 | ±0.06 | ±0.12 | ±0.24 | ±0.48 | | >6 – 10 | ±0.08 | ±0.15 | ±0.30 | ±0.60 | | >10 – 18 | ±0.10 | ±0.20 | ±0.40 | ±0.80 | | >18 – 30 | ±0.12 | ±0.25 | ±0.50 | ±1.00 | | >30 – 50 | ±0.15 | ±0.30 | ±0.60 | ±1.20 | | >50 – 80 | ±0.20 | ±0.40 | ±0.80 | ±1.60 | | >80 – 120 | ±0.25 | ±0.50 | ±1.00 | ±2.00 | | >120 – 180 | ±0.30 | ±0.60 | ±1.20 | ±2.40 | | >180 – 250 | ±0.40 | ±0.80 | ±1.60 | ±3.20 |

Note: Actual values in the official standard vary by material (e.g., glass-filled, amorphous, crystalline). The above is an illustrative summary.

If you have previously used other tolerance standards, here is how ISO 20457 fits into the family: iso 20457 tolerance table pdf

ISO 20457 typically specifies tolerances for outside diameters in a "step" format. The tolerance increases as the pipe size increases.

Example Concept Table (Simplified for Group 2 Materials like PE/PP):

| Nominal Outside Diameter ($d_n$) (mm) | Tolerance (mm) | | :--- | :--- | | $d_n \le 16$ | +0.3 / 0 | | $16 < d_n \le 63$ | +0.4 / 0 | | $63 < d_n \le 110$ | +0.5 / 0 | | $110 < d_n \le 160$ | +0.6 / 0 | | $160 < d_n \le 225$ | +0.7 / 0 | | ... | ... | Below is a representative example of the tolerance

Note: The format +X / 0 indicates that the pipe can be larger than nominal by X mm, but cannot be smaller than the nominal size (ensuring it can seal).

The free search for an **“iso 20457 tolerance table pdf”” will often yield incomplete versions. The complete official PDF contains more than just the tolerance table. It includes:

If you are designing high-volume medical or automotive parts, the full PDF is a necessary investment. For prototyping or low-volume industrial design, a high-quality summary table combined with good communication with your moulder may suffice. Note: Actual values in the official standard vary

As we move toward Industry 4.0 and Model-Based Definition (MBD), the ISO 20457 tolerance table PDF is evolving into a machine-readable format. Future revisions may come as XML or JSON files that CAD systems read automatically. However, for the next decade, the PDF will remain the universal backup—the human-readable master key.

ISO 20457 is the first international standard dedicated exclusively to the dimensional tolerances of injection-moulded and compression-moulded plastic parts. Published in 2020, it replaces the outdated practice of applying metal-based tolerance systems (like ISO 286) to polymers.

The standard acknowledges that plastics are viscoelastic. Their final dimensions depend on:

Because of these variables, ISO 20457 provides a structured tolerance system that balances precision against manufacturing reality. It offers four tolerance classes (fine, medium, coarse, very coarse) that correlate with the complexity of the moulded feature.