Iso 20457 Tolerance Table Pdf | No Ads |
The standard provides general tolerances for linear dimensions, radii, angular dimensions, flatness, concentricity, roundness, and surface profile.
| Nominal Size Range (mm) | Fine (f) Tolerance (± mm) | Medium (m) Tolerance (± mm) | Coarse (c) Tolerance (± mm) | | :--- | :--- | :--- | :--- | | 0.5 up to 3 | 0.05 | 0.1 | 0.2 | | 3 up to 6 | 0.1 | 0.2 | 0.5 | | 6 up to 30 | 0.2 | 0.5 | 1.0 | | 30 up to 120 | 0.3 | 0.8 | 1.5 | | 120 up to 400 | 0.5 | 1.2 | 2.5 | | 400 up to 1000 | 0.8 | 2.0 | 4.0 | | 1000 up to 2000 | 1.2 | 3.0 | 6.0 | | 2000 up to 4000 | 2.0 | 5.0 | 10.0 |
Specifying functionally required tolerances based on polymer behavior. Toolmakers Agreeing on shrinkage compensation and tool contour limits. Quality Engineers Applying acceptance criteria in production control plans. Tolerance Group (TG) table breakdown for a particular nominal dimension range? TOLERANCES
ISO 20457 is the internationally recognized standard for tolerances and acceptance conditions of plastic molded parts. This comprehensive guide explains everything you need to know about the ISO 20457 tolerance table, how to interpret tolerance grades, and where to obtain the official PDF documentation. iso 20457 tolerance table pdf
ISO 20457 supersedes the earlier German standard DIN 16742 (originally published in 2013). The new ISO version does not introduce major changes but rather standardizes the well-established German approach at the international level. Manufacturers and engineers accustomed to DIN 16742 will find ISO 20457 familiar and directly applicable.
Do not apply tight tolerances to the whole part. Mark functional fitment areas with specific limits, and let non-critical housings fall back on general TG6 or TG7 rules.
ISO 20457:2018 is the primary international standard for determining for non-porous plastic molded parts. It replaces the older DIN 16742 standard and provides a systematic way to calculate achievable tolerances based on material properties and manufacturing processes. Unlike metal machining standards, ISO 20457 accounts for the unique behavior of plastics, such as mold shrinkage and environmental sensitivity. Key Components of ISO 20457 This comprehensive guide explains everything you need to
Master Guide to ISO 20457 Tolerance Tables for Plastic Molded Parts Direct Answer First
Defines TG1 (highest precision) to TG7 (lowest precision), with TG6 being common for typical thermoplastic applications.
The tolerance standards applicable for metal parts cannot be adopted for plastic structures or can only be applied to a very limited extent, which is precisely why ISO 20457 was developed. Plastic part variation comes from material shrinkage, cooling rate, and process fluctuation—not just from mold steel precision. as noted by tolerance experts
Disclaimer: This article is for informational purposes. Always refer to the official ISO 20457:2018 document for legally binding tolerance values and definitions.
An important distinction exists between and ISO 22081 . While both standards address general geometrical specifications, they serve different purposes. ISO 22081 specifies general geometrical tolerances using surface profile as a geometric feature—either without datums or with a datum system that blocks all non-redundant degrees of freedom. By contrast, ISO 20457 provides a distance-dependent tolerance zone width approach specifically designed for plastics, recognizing that shrinkage effects cause dimensional variation proportional to the distance between features. However, as noted by tolerance experts, ISO 20457 does not fully implement the distance-dependent approach consistently throughout the standard.
The standard distinguishes between two fundamental types of dimensions based on their relationship to the mold:
The ISO 20457 tolerance table provides a detailed list of tolerances for various features, including: