The standard applies to non-porous molded parts made from thermoplastics, thermoplastic elastomers, and thermosets. If agreed upon by contractual parties, the standard can also be applied to other plastic processes.
Engineers utilize the as a primary tool to balance part functionality with production economics. Understanding the tolerance groups (TG), material shrink behaviors, and evaluation rules outlined in the standard is critical for successful part design. iso 20457 tolerance table pdf
For manufacturing engineers, purchasing the official ISO 20457:2018 PDF from your national standards body is an essential investment. The standard belongs on every plastics engineer’s reference shelf alongside ISO 2768 (for machined components) and ISO 22081 (for surface profile tolerancing). The standard applies to non-porous molded parts made
To ensure your manufacturer interprets your designs correctly, follow these documentation standards on your engineering prints: Understanding the tolerance groups (TG)
It covers geometric dimensioning and tolerancing (GD&T) specific to plastics, including straightness, flatness, and roundness.
It includes specifications for surface profiles, angular dimensions, and tool offsets (parting lines). OKW Gehäusesysteme Reference Documents & Tables
Mastering Plastic Molding Precision: The Definitive Guide to the ISO 20457 Tolerance Table