ISO 20457 Tolerance Group 5 (TG5) serves as the "standard" or baseline precision grade for plastic injection molded parts. It is the most commonly applied tolerance series for industrial and consumer plastic products where high precision is desired without the extreme manufacturing costs of high-precision grades like TG1-TG3. Core Function and Classification
for industrial injection molding. It is often applied to functional parts where fit is critical but extreme "toolroom" precision (like TG1 or TG2) is not required. Key Requirements
ISO 20457:2018 (which replaced DIN 16742) provides a standardized framework for specifying geometrical and dimensional tolerances based on the specific behavior of polymers, such as mold shrinkage and post-production changes. Within this framework, TG5 represents the following: Precision Level: Standard precision applications. Iso 20457 Tg5
ISO 20457, also known as "Biological and clinical evaluation of medical devices for skin contact - Part 5: Test for irritation and delayed-type hypersensitivity," is an international standard developed by the International Organization for Standardization (ISO). This standard provides guidelines for the biological evaluation of medical devices that come into contact with the skin, specifically focusing on the assessment of irritation and delayed-type hypersensitivity reactions.
Applications and Performance Considerations
TG5 is intended for components subjected to cyclic loading, abrasive contact, or elevated service stress—examples include gears, shafts, bearings, forging dies, and wear-critical tooling. Designers choose TG5 where resistance to surface wear must be paired with sufficient core toughness to resist crack initiation and propagation. In applications where corrosion resistance is a factor, TG5 may require surface treatments, coatings, or selection of an alternate stainless grade. ISO 20457 Tolerance Group 5 (TG5) serves as
ISO 20457 (which replaced DIN 16742) provides a framework for agreeing on dimensional, shape, and position deviations in plastics, which behave differently than metals due to shrinkage and polymer properties.
Conclusion
ISO 20457 TG5 provides a defined specification for a high-performance ferrous grade combining wear resistance, strength, and toughness via controlled chemistry and heat treatment. Its use is common in engineering components subject to mechanical wear and cyclic loads; compliance with the standard ensures predictable performance, quality traceability, and suitability for demanding industrial applications. It is often applied to functional parts where
For specific numerical values for your part's dimensions, you can reference the full standard available through the or technical distributors like against the older classes to see how your legacy designs might transition? Go to product viewer dialog for this item.