"If this shrinks even a fraction too much, the internal circuitry won't slide in," his lead toolmaker, Hans, warned. "And Polyamide loves to move. It’s like trying to cage a ghost." The challenge was twofold:
TG5 assumes (typically ±0.2% to ±0.5% absolute shrink depending on material). din 16742 - tg5
TG5 assumes dimensional stability at 23°C / 50% RH. If your part operates at 80°C in PA66, the tolerance must be loosened by 25% due to creep—or switch to glass-filled material. "If this shrinks even a fraction too much,
This test method, also known as TG5, is used to determine the thermal stability and decomposition behavior of thermoplastic materials using thermogravimetry (TG). TG5 assumes dimensional stability at 23°C / 50% RH
: Achieving TG5 often requires materials with lower shrinkage rates (e.g., amorphous resins like PC or ABS) rather than high-shrinkage semi-crystalline materials. Key Tolerance Concepts