Din 16742 - Tg5 2021 Jun 2026

DIN 16742 is a German manufacturing standard published by the Deutsches Institut für Normung (DIN). It provides a structured system for determining dimensional tolerances and variations in plastic molded parts. The standard covers injection molding, compression molding, injection compression molding, and rotational molding.

It classifies materials into different accuracy groups, which then determine the applicable Tolerance Group. Deep Dive into Tolerance Group 5 (TG5)

When evaluating the numerical values assigned to , a critical distinction must be made between how features are formed inside the mold cavity. 1. Tool-Fixed Dimensions (Werkzeuggebundene Maße)

Multi-stage holding pressure profiles in the injection molding machine. High-precision CNC-machined or EDM-machined steel molds. 4. How Tolerances are Calculated Under TG5 din 16742 - tg5

: Dimensions affected by moving mold parts (like the parting line or sliders). These require larger tolerances to account for machine shifting or clamping variations. Design Considerations for TG5

Unlike tolerance standards originally developed for metal parts, DIN 16742 recognises that polymers behave fundamentally differently during processing and in service. Plastics exhibit anisotropic shrinkage, viscoelastic behaviour, and strong dependence on processing parameters such as injection pressure, holding pressure, mould temperature, and melt temperature.

Precise mold temperature control units (variothermal systems). DIN 16742 is a German manufacturing standard published

However, there are challenges. The primary challenge is ensuring compliance and verifying that tool holders meet the standard's requirements. This often involves third-party inspection and certification processes. Additionally, as technology evolves, standards must be periodically reviewed and updated, which can be a resource-intensive process.

TG5 is typically applied to parts that require a reliable fit in mechanical assemblies, such as housings for electronics, automotive interior components, and consumer appliances.

When an engineering drawing designates general tolerances according to , it explicitly balances tight, high-accuracy geometry with a cost-effective, reproducible manufacturing window. 🛠️ The Mechanics of DIN 16742 commercial tolerances) to TG9 (ultra-precise

Plastics shrink as they cool, but they do not all shrink equally. DIN 16742 classifies materials into evaluation groups based on their shrinkage behavior:

Dimensions formed by a single mold part (mold-fixed) are easier to control than those affected by moving mold elements (non-mold-fixed). "Steel Off" Optimization:

In DIN 16742, Tolerance Groups dictate how strictly a dimension must be controlled. The scale runs from TG1 (extremely loose, commercial tolerances) to TG9 (ultra-precise, rarely achievable tolerances).

Understanding DIN 16742 - TG5 is the central German engineering standard for determining tolerances in plastic molded parts. Within this framework, TG5 (Tolerance Group 5) represents the "baseline" or "standard" precision level for modern injection molding.

TG5 enforces flatness, roundness, and parallelism. A TG5 part cannot simply have the right width; its side walls must be straight within 0.1 mm over 100 mm.