ISO 20457 simplifies this by establishing a series of tolerance groups, ranging from NW (non-functional dimensions) to various TG (Tolerance Group) levels. These levels define the allowable dimensional variations based on the material characteristics and the production process. What is Tolerance Group 5 (Tg5)?
ISO 20457 replaced the older ISO 8062 and is the global definitive standard for specifying what is "technically feasible" in plastic injection molding. Unlike metal machining, plastic tolerances must account for complex factors like , thermal expansion, and moisture absorption. Understanding the TG5 Classification
ISO 20457:2018 ("Plastics — Tolerances for moulded components") is the international standard that superseded the old German DIN 16901 standard. It was designed to provide a more modern, globally applicable framework for defining acceptable dimensional deviations for plastic molded parts.
To give you a better sense of where TG5 fits, here's a comparison of common tolerance groups used in injection molding:
: Dimensions affected by the moving parts of the mold, such as parting lines, slides, or core pulls. These require wider tolerances due to mechanical clearances. Application Examples for TG5 Iso 20457 Tg5
The fifth search for "ISO 20457 Tg5 standard" returned some results.
An engineer cannot simply mandate "ISO 20457 TG5" on a blueprint and guarantee compliance. Achieving it requires stabilizing a complex chain of variables across the product lifecycle.
The circular economy for plastics is often discussed in terms of grand ambitions: zero waste, closed-loop systems, and carbon neutrality. However, the reality of recycling is far more granular. It depends on micrometers, melt flow rates, and the chemical compatibility of additives.
She was the convenor of —a sub-group buried deep within the labyrinthine machinery of ISO 20457 . The public had never heard of it. Most engineers hadn’t either. But TG5 held the keys to hell. ISO 20457 simplifies this by establishing a series
specifically for plastic molded parts to account for the unique behavior of polymers compared to metals. Super-Ingenuity ISO 20457 TG5 Overview
The full text of (Plastics moulded parts — Tolerances and acceptance conditions) is a copyright-protected document and is not available for free legally online. However, it can be purchased from authorized standards organizations or viewed through specific preview tools. Where to Access the Full Paper
Specifying TG5 on a drawing requires defining accompanying parameters for valid measurement, such as the acceptance temperature (usually 23∘C23 raised to the composed with power cap C ) and measurement humidity.
What specific or resin blend are you planning to use? ISO 20457 replaced the older ISO 8062 and
The second search for "ISO 20457 Tg5 pneumatic" returned some relevant results (0,1,2,5) and some irrelevant ones.
What or polymer blend are you planning to use?
*Note: Exact limits depend heavily on whether the specific feature is bound to a single tool cavity or spans across a parting line. 3. Factors Leading to a Tg5 Classification