Iso 20457 Tolerance Table Pdf Here
ISO 20457
is the current international standard for determining manufacturing tolerances of plastic molded parts . It replaces older standards like ISO 8062 and is closely aligned with the German DIN 16742. This standard is vital for designers and manufacturers to agree on achievable precision without driving up costs through unnecessary accuracy requirements. Key Tolerance Groups (TG)
The official PDF contains worked examples and the calculation formulas — but not a single lookup table like ISO 2768. iso 20457 tolerance table pdf
Unlike metal parts, plastic tolerances must account for processing shrinkage, tool binding, and material properties. Geometrical Tolerancing: ISO 20457 is the current international standard for
- Material family (amorphous vs. semi-crystalline)
- Mould design (gate location, cooling channels)
- Processing parameters (melt temperature, packing pressure)
- Post-moulding conditions (humidity absorption, annealing)
- Do not risk free, illegal PDFs. Use official previews or purchase the standard.
- Always match the tolerance class to the functional need: Fine for precision, Medium for general, Coarse for rough.
- Remember that the table works alongside, not instead of, specific fit standards like ISO 286.