In injection molding, dimensions are split into tool-specific (dimensions formed within a single mold half or core) and non-tool-specific (dimensions crossing a moving mold parting line or slider). Tg5 explicitly dictates the permissible symmetrical limit deviation based on the nominal dimension size of the part. Nominal Dimension Range (mm) Tg5 Symmetrical Limit Deviation (± mm)* Typical IT Grade Mapping ± 0.05 mm to ± 0.08 mm IT11 / IT12 6 mm to 30 mm ± 0.10 mm to ± 0.15 mm IT12 / IT13 30 mm to 120 mm ± 0.18 mm to ± 0.25 mm IT13 / IT14 120 mm to 400 mm ± 0.30 mm to ± 0.50 mm IT14 / IT15
Specifying TG5 is a strategic choice made during the design for manufacturing (DFM) phase. Designers should consider TG5 for: Iso 20457 Tg5
Achieving a TG5 rating is significantly easier and more cost-effective with low-shrinkage materials. For high-shrinkage materials, achieving TG5 requires strict processing controls and advanced mold cooling systems. 2. Dimension Types: Element vs. Tool-Specific Designers should consider TG5 for: Achieving a TG5
Unlike virgin polymers with fixed properties, recyclates degrade with each loop. TG5’s current framework is static—it grades a single batch. It does not yet offer a “looping index” that predicts how many cycles a given recyclate can survive before falling below a grade threshold. This is a known gap that TG5 is currently addressing in a planned revision. Dimension Types: Element vs