Din 16742 - Tg5

: Reaching this group usually requires more rigorous process control and quality assurance than general-purpose molding. Comparison within the Standard Tolerance Group Typical Application Classification TG4 Critical interfaces, bearing seats High Precision TG5 Functional fits, standard precision parts Accurate Production TG6 General housings, enclosures Standard Production TG7/8 Large cosmetic covers, foam molding Reduced Precision Practical Application Tips

Semi-crystalline polymers form organized, tight structures as they freeze. This leads to high, highly directional shrinkage (often 1.0% to 2.5%), making TG5 significantly harder to achieve without strict process controls.

: Features formed by a single mold component (e.g., a cavity insert). These feature tighter tolerances because tool movements do not affect them.

injection-moulding-tolerances-din16742-2013.pdf - Xometry Pro

The standard doesn't just provide a table of numbers; it calculates tolerances based on several variables: 1. Mold-Fixed vs. Non-Mold-Fixed Dimensions din 16742 - tg5

DIN 16742 TG5: A Comprehensive Guide to Precision Plastic Molding Tolerances

TG5 is widely used as the default standard for conventional injection molding, vacuum casting, and other low-pressure processes.

TG5 is achievable with a broad range of thermoplastics, especially when the production process is reasonably well controlled. Common materials that can reliably achieve TG5 tolerances include:

The selection of TG5 is typically driven by the material choice and the part geometry. : Reaching this group usually requires more rigorous

The addition of glass fibers, carbon fibers, or mineral fillers reduces overall volumetric shrinkage. Filled materials make it significantly easier to hit the tight dimensional windows demanded by TG5. Tooling and Processing Achieving TG5 requires:

Variations in wall thickness cause localized differences in cooling rates. This leads to uneven shrinkage, sink marks, and warping that can instantly push a part outside of TG5 limits. Incorporate Generous Draft Angles: Implement a minimum of 1∘1 raised to the composed with power 2∘2 raised to the composed with power

: Variations in wall thickness cause differential cooling, leading to localized shrinkage, sink marks, and warpage that will break TG5 limits.

Form, position, and orientation tolerances are considered alongside linear dimensions to prevent unexpected assembly issues. Economic Considerations of TG5 : Features formed by a single mold component (e

Note: For large parts, TG5 may be unnecessarily expensive or technically challenging to achieve due to significant shrinkage; in such cases, is preferred. Calculating DIN 16742 TG5 Tolerances

2. Non-Tool-Fixed Dimensions (Nicht werkzeuggebundene Maße)

The standard defines nine distinct tolerance groups (), where lower numbers represent tighter, more expensive precision and higher numbers represent wide, structural tolerances.