Din 16742 - Tg5 -

Within this standard, represents a high-precision classification. It is typically applied to parts that require tight functional fits, consistent assembly behavior, or superior geometric stability without resorting to post-molding machining.

| Nominal Size Range (mm) | Approximate Tolerance Class TG5 (mm) | Practical Interpretation | |------------------------|--------------------------------------|---------------------------| | 0 – 10 | ±0.05 to ±0.08 | Very tight; requires stable process & precision mold. | | 10 – 50 | ±0.08 to ±0.12 | Typical for functional bearing/shaft fits. | | 50 – 160 | ±0.12 to ±0.20 | Demanding for larger parts; watch for warpage. | | 160 – 400 | ±0.20 to ±0.35 | High precision for large geometries; design must minimize stress. | Note: Actual values depend on material shrinkage, part geometry, and feature type (free dimension vs. fixed dimension). Always refer to the latest DIN 16742 tables.

For critical features, it is strongly recommended to specify TG5 only on functionally relevant dimensions, while allowing coarser grades (e.g., TG8–TG10) on non-critical geometries to balance cost and performance.

DIN 16742 is the German industry standard governing . It replaces the older standards DIN 16901 and VW 13010, providing a unified, modern system for defining form, orientation, and dimensional accuracy.

While the full standard includes complex tables based on nominal size ranges, TG5 can be summarized as: