Din 16742: - Tg5

DIN 16742 is a German standard (adopted internationally as ISO 20457) that defines general tolerances for plastic molded parts. Unlike metal parts, which can be specified using standardized fit systems, plastic parts require a unique system due to material behavior like shrinkage, warpage, and moisture absorption.

Crucial for dynamic parts like gears or fluid seals where deviations cause failure.

: Polyamide (PA) is notorious for medium to high shrinkage.

Injection moulding is the primary manufacturing method associated with TG5. For prototype and low-volume production, can also achieve TG5 tolerances, with a minimum tolerance of ±0.1 mm and general tolerances of 0.4 – 0.5% of the nominal dimension.

, referencing DIN 16742 TG5 is a clear signal of engineering rigor and quality expectations. Current Status & Replacement din 16742 - tg5

The allowable deviation under TG5 depends dynamically on the overall nominal size of the dimension. Larger spans require larger tolerance bands to accommodate cumulative material shrinkage. Nominal Dimension Range (mm) Tool-Specific Tolerances (W) Non-Tool-Specific Tolerances (NW) ±0.05plus or minus 0.05 ±0.08plus or minus 0.08 > 6 to 30 ±0.10plus or minus 0.10 ±0.15plus or minus 0.15 > 30 to 120 ±0.18plus or minus 0.18 ±0.25plus or minus 0.25 > 120 to 500 ±0.35plus or minus 0.35 ±0.50plus or minus 0.50 > 500 to 1000 ±0.60plus or minus 0.60 ±0.85plus or minus 0.85

Reserved for extreme or high-precision parts (e.g., medical connectors or aerospace components).

For dimensions on inclined surfaces (due to draft), to ensure consistent two-point measurements. This prevents disputes about where exactly on the draft surface the measurement should be taken.

The DIN 16742 standard establishes a comprehensive framework comprising nine distinct tolerance groups () to classify manufacturing accuracy. DIN 16742 is a German standard (adopted internationally

This guide breaks down , the primary German and European standard for plastic part tolerances, with a specific focus on Tolerance Group 5 (TG5) 1. What is DIN 16742?

: Standards like DIN 16742 facilitate the interchangeability of tool holders across different machines and manufacturers. This not only offers flexibility in production planning but also helps in reducing inventory levels, as a standard tool holder can be used in various machines.

Understanding DIN 16742 - TG5: The Standard for Plastic Precision

A "TG5" claim on a drawing is meaningless without verification. The standard requires: : Polyamide (PA) is notorious for medium to high shrinkage

These dimensions are formed within a single, solid piece of the mold. Because there are no moving components or splitting parting lines interacting to form this specific shape, the variation relies entirely on the material's shrinkage consistency. As a result, tool-fixed dimensions carry much tighter tolerances in the TG5 matrix.

Reserved for high-precision, custom toolmaking applications.

TG5 serves as the default general tolerance for features like linear dimensions, radii, and draft angles. It is specified in procurement documents, part drawings, and CAD data.