Din 16742 - Tg5 [extra Quality]

All tolerances are symmetrical ((\pm)). A practical minimum tolerance of is generally applied regardless of what the table might yield for very small nominal sizes.

| Criteria | Requirement | |--------------------------------|-------------------------------------------------------| | Typical tolerance at 50 mm | ±0.30 mm | | Draft angle for 30 mm depth | ≥ 1.0° per side | | Geometric tolerance per 100 mm | 0.25 – 0.30 mm | | Suitable materials | Most unfilled thermoplastics, some filled compounds | | Inspection condition | 23°C, 24h after molding | | Cost impact | Neutral – standard |

: While the exact numerical deviation depends on the nominal dimension of the part, TG5 typically allows for general tolerances in the range of ±0.1 mm to ±0.5% .

For a 50 mm flat surface in TG5, permissible flatness deviation is roughly . Compare to TG8 (0.02 mm) which requires mirror-finish tool surfaces.

| Series | Name | P₅ value | Description | Cost impact | |--------|-------------------------|----------|--------------------------------------------------------------------------|-------------------------| | 1 | Normal production | 0 | General tolerances apply; dimensional accuracy not a primary quality focus | Standard cost | | 2 | Precise production | –1 | Production and QA oriented toward higher accuracy requirements | Moderate surcharge | | 3 | Precision production | –2 | Full alignment of production and QA to very high accuracy requirements | Significant surcharge | | 4 | Special precision production | –3 | As series 3, but with intensified process monitoring | Highest cost; agreement mandatory | din 16742 - tg5

⚠️ These are general linear tolerances. For functional features (e.g., fits with metal parts), tighter TG3 or TG4 is recommended.

To reach the tight requirements of TG5, engineers often use a "Steel Off"

Dimensional tolerances depend on the (mm) of the feature. Below is a simplified table for TG5 (based on DIN 16742, general tolerances for non-critical dimensions):

Engineers must also specify if a dimension is (formed by a single part of the tool) or non-mold-fixed (affected by the moving parts of the mold), as non-mold-fixed dimensions typically require slightly larger tolerances due to tool movement. Summary Table: Tolerance Group Comparison Tolerance Group Application Level Common Use Cases TG1 - TG3 Extreme Precision Micro-electronics, Aerospace TG4 High Precision Medical devices, fine gears TG5 Standard Precision General Injection Molding (Industrial) TG6 Commercial/Coarse Consumer goods, packaging TG7+ Very Coarse Structural foam, heavy construction Practical Advice for Designers All tolerances are symmetrical ((\pm))

Materials with very high shrinkage or strong anisotropic behaviour (e.g., unfilled PP, unfilled PA6) may still be processed to TG5, but often require more careful process optimisation or moving to Series 2 production.

DIN 16742 – TG5 stands as the workhorse tolerance group for injection‑moulded plastic parts. It represents the achievable accuracy of a competent moulding operation operating under normal production conditions, balancing precision against cost. With symmetrical tolerances ranging from ±0.05 mm for small tool‑bound dimensions to ±1.40 mm for large non‑tool‑bound dimensions, TG5 covers the vast majority of functional plastic parts in automotive, consumer goods, electrical and medical device industries.

An essential rule when navigating DIN 16742 - TG5 is classifying dimensions based on tool boundaries. The standard establishes two distinct categories: Tool-Specific Dimensions (W)

injection-moulding-tolerances-din16742-2013.pdf - Xometry Pro For a 50 mm flat surface in TG5,

The feature is designed for engineers, designers, and technicians working in various industries, such as mechanical engineering, automotive, aerospace, and manufacturing, who need to perform tolerance analysis and calculation according to DIN 16742 - TG5.

| Nominal size range (mm) | TG5 – W tolerance (± mm) | TG5 – NW tolerance (± mm) | |------------------------|-------------------------|--------------------------| | 1 to 3 | 0.05 | 0.08 | | > 3 to 6 | 0.08 | 0.11 | | > 6 to 10 | 0.11 | 0.14 | | > 10 to 18 | 0.14 | 0.17 | | > 18 to 30 | 0.17 | 0.20 | | > 30 to 50 | 0.20 | 0.23 | | > 50 to 80 | 0.23 | 0.36 | | > 80 to 120 | 0.36 | 0.50 | | > 120 to 180 | 0.50 | 0.58 | | > 180 to 250 | 0.58 | 0.65 | | > 250 to 315 | 0.65 | 0.70 | | > 315 to 400 | 0.70 | 1.00 | | > 400 to 500 | 1.00 | 1.40 |

A "TG5" claim on a drawing is meaningless without verification. The standard requires:

To successfully produce parts in Series 3 or 4, the following conditions must be met: