If you are looking at an ISO 20457 PDF, you will see columns labeled:
Reserved for optimized, premium engineering plastics molded under tightly regulated laboratory or high-end cleanroom conditions. Tooling costs are exceptionally high.
You can purchase the official standard from national bodies:
| Nominal Wall Thickness ($e_n$) (mm) | Tolerance (mm) | | :--- | :--- | | $3.0 < e_n \le 4.0$ | $\pm 0.5$ | | $4.0 < e_n \le 5.0$ | $\pm 0.6$ | | $5.0 < e_n \le 6.0$ | $\pm 0.7$ | | $6.0 < e_n \le 7.0$ | $\pm 0.8$ |
The official PDF of ISO 20457:2018 can be purchased from several authorized national standards bodies and online retailers. These include the (available for preview on the ISO Online Browsing Platform), the British Standards Institution (BSI) , and the Intertek Inform standards store. National adoptions, such as the German DIN ISO 20457:2021-06 and the British BS ISO 20457:2018 , are also available and are technically identical to the international version. The official PDF typically costs around CHF 100 or more, depending on the distributor.
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Whether you are a veteran designer or new to plastic part manufacturing, gaining a thorough understanding of and access to the ISO 20457 tolerance table PDF is not just a best practice—it is a necessity for modern, competitive manufacturing.
While DIN 16901 is still referenced for legacy parts, .
The is more than a grid of numbers; it is a strategic tool for balancing cost and quality. By understanding the three tolerance classes (Fine, Medium, Coarse) and knowing how to navigate the linear and angular tables, you can produce drawings that are both professional and manufacturable.
Look for "ISO 20457:2018 – Preview" on the ISO website. The free preview usually includes the scope, the first few pages, and crucially, the main tolerance table . For many internal design purposes, the preview table is sufficient, though you should buy the full standard for legal manufacturing contracts.
which includes the first few pages and Table 8 (General Tolerances). Detailed Overviews