Searching for an typically means you want immediate access to these numerical values without purchasing the full 30-page document. However, understanding the logic behind the table is essential before applying any numbers.
The accuracy of the mold cavity design and construction.
The standard uses a system of (Plastics Tolerances), similar to the IT grades in ISO 286. However, PT grades are generally wider than metal IT grades for the same nominal size. iso 20457 tolerance table pdf
ISO 20457 categorizes tolerances into two distinct application groups based on whether the dimensions are tool-dependent or affected by post-molding assembly processes: 1. Series NW (Non-Tool-Dependent / Assembly Tolerances)
For design engineers and procurement professionals, downloading an is essential to establish standardized, cost-effective, and technically achievable manufacturing boundaries. Setting excessively tight tolerances drives up mold tooling costs exponentially, while overly loose parameters risk assembly failures. This article breaks down how the standard works, how to read the tables, and why it is critical for modern plastics manufacturing. What is ISO 20457:2018? Searching for an typically means you want immediate
For example, at TG6, a 30–50 mm nominal dimension would have:
The defines acceptable manufacturing deviations to: The standard uses a system of (Plastics Tolerances),
Below is a representative example of the from ISO 20457 (values in mm, for general-purpose unfilled plastics):
Complete Guide to the ISO 20457 Tolerance Table Specifying the correct dimensional limits for plastic parts is one of the most critical challenges in modern manufacturing. Unlike rigid metals, polymers exhibit complex behaviors like high thermal expansion, molecular orientation, and significant volumetric shrinkage. To address these unique properties, the International Organization for Standardization developed ( Plastics molded parts — Tolerances and acceptance conditions ).
The precision of the mold cavity itself. CNC machining, EDM wire cutting, and mold wear over time dictate this baseline accuracy. 2. Molding Process Variations
