Din 16742 - Tg5 May 2026

Under the DIN 16742 standard, Tolerance Group 5 (TG5) represents a precision-oriented classification for plastic molded parts. It is typically applied to dimensions where standard production tolerances (like TG6) are insufficient but ultra-high precision (like TG3 or TG4) would be cost-prohibitive. Key Characteristics of TG5

Precision Level: TG5 is often categorized as "Accurate Production" for various thermoplastics.

Achievability: While standard injection molding often defaults to TG6 for general dimensions, TG5 is considered a feasible standard for high-quality parts when the process is well-optimized.

Material Influence: Achieving TG5 depends heavily on material behavior. For example, low-shrinkage materials like ABS are easier to hold to TG5 than crystalline materials (e.g., PA or POM) which exhibit higher shrinkage and warpage.

Process Stability: 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

DIN 16742 is the German industrial standard used to define manufacturing tolerances and acceptance conditions for plastic moulded parts. It replaced the older DIN 16901 and is often used alongside or as a reference for the international standard ISO 20457. Tolerance Group 5 (TG5) Overview

TG5 is a specific accuracy class within this standard. In the hierarchy of tolerance groups (TG1–TG9), TG5 is considered a "precise" or "standard precision" class for high-quality injection moulding.

Application: It is typically used for functional parts with moderate to high dimensional accuracy requirements, such as precision mechanical components or mating interfaces.

Production Level: Generally falls under Series 2 (Accurate Production), meaning production and quality assurance are oriented toward higher dimensional stability than standard commercial grades (like TG6).

Material Influence: 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 din 16742 - tg5

When applying TG5 under DIN 16742, dimensions are categorized based on how they are formed in the tool:

Tool-Specific Dimensions (W): Dimensions formed by a single, solid part of the mould. These typically have tighter tolerances because they are not affected by mould movement.

Non-Tool-Specific Dimensions (NW): Dimensions affected by moving mould parts (e.g., across the parting line, sliders, or lifters). These require larger tolerances to account for mechanical play in the mould. Standard Acceptance Conditions

For measurements to be valid under DIN 16742, parts must be conditioned according to DIN EN ISO 291: Temperature: Humidity: relative humidity.

Timing: Measurements should typically be taken between 16 and 72 hours after production to allow for shrinkage stabilization. Tolerance Comparisons

While specific values for TG5 vary by nominal dimension (e.g., 1–3mm vs. 500–630mm), it sits between the high-precision TG4 (used for medical devices/gears) and the standard industrial TG6 (used for general housings).

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

A very specific request!

DIN 16742 is a German standard for "Plastics - Thermoplastic materials - Test methods for determination of thermal properties". Under the DIN 16742 standard, Tolerance Group 5

The "TG5" likely refers to a specific test method within this standard.

Here's a brief overview:

DIN 16742 - TG5: Thermogravimetry (TG) test

This test method, also known as TG5, is used to determine the thermal stability and decomposition behavior of thermoplastic materials using thermogravimetry (TG).

The test involves measuring the mass change of a sample as a function of temperature, typically in a inert atmosphere. This allows for the identification of decomposition temperatures, mass loss rates, and residual masses.

If you need the full text of the standard, I recommend checking the following sources:

1. DIN (Deutsches Institut für Normung) website: You can purchase the standard directly from the DIN website.
2. International standards databases: Some databases, like IHS Standards Store or ANSI Webstore, may offer access to DIN standards, including DIN 16742.
3. Technical libraries or universities: Many technical libraries and universities have access to standards collections, including DIN standards.

The feature regarding DIN 16742 TG5 refers specifically to the tolerance grade for thermoplastics injection molded parts.

Here is the precise technical feature of TG5 within the standard:

2. Functional Requirements

Designers select TG5 for features that are: DIN (Deutsches Institut für Normung) website : You

• Non-critical assembly points (e.g., clearance holes).
• Aesthetic or protective covers where fitment gaps are acceptable.
• Large structural elements where slight warping does not impact structural integrity.

Achieving Optical Perfection: A Deep Dive into DIN 16742 – TG5

In the world of injection-molded plastic components, a frequent source of friction between designers and manufacturers is surface quality. Designers demand "perfect" parts, while production managers speak in microns and shrinkage rates. The German standard DIN 16742 bridges this gap. At its peak sits TG5—the highest tolerance grade for surface finish and geometry.

The Challenge: Why TG5 is Difficult

Many molders hesitate to guarantee TG5 for three reasons:

• Material Dependency: Semi-crystalline plastics (POM, PA6) shrink anisotropically. Holding TG5 requires advanced simulation (Moldflow) and possibly post-molding annealing.
• Tooling Cost: Achieving TG5 demands a hardened mold steel (e.g., 1.2343 ESR), high-precision EDM electrodes, and multi-point temperature control. A TG5 mold costs 30–50% more than a TG3 mold.
• Process Window: The injection pressure, hold pressure, and cooling time must be statistically controlled (Cpk ≥ 1.33). Ambient humidity changes alone can push a TG5 part out of spec.

Overview of DIN 16742

Unlike standards for machined metal parts, DIN 16742 accounts for the unique behavior of plastics. The standard distinguishes between two types of dimensions:

1. Dimensions dependent on the mold (Molded Dimensions): Features formed directly by the mold cavity (e.g., external widths, internal holes).
2. Dimensions not dependent on the mold (Deformation Dimensions): Features influenced by the warping or distortion of the part after ejection (e.g., distances across a flat wall, angularity).

The standard assigns tolerance values based on the nominal dimension and the selected Tolerance Group.

Mastering Precision: A Deep Dive into DIN 16742 - TG5 for Plastic Injection Molding

In the world of plastic injection molding, precision is not just a luxury—it is a contractual obligation. When an engineer specifies a tolerance, they are defining the functional limits of a part. However, not all tolerances are created equal. While general standards like ISO 20457 or ISO 286-2 exist, the German standard DIN 16742 reigns supreme for plastic components. Within this standard, the classification TG5 represents the "sweet spot" between high precision and economic manufacturability.

This article explores everything you need to know about DIN 16742 - TG5: its definition, mathematical foundations, practical applications, and how it compares to other tolerance classes.

Conclusion

DIN 16742 - TG5 serves as a pragmatic specification in plastic engineering. It acknowledges that not all plastic parts require the precision of machined metal. By utilizing TG5, engineers can design parts that are functional and manufacturable using materials like Polypropylene or Polyethylene without imposing unrealistic quality constraints, ultimately leading to more robust and cost-effective production.

The Significance of DIN 16742 - TG5: A Comprehensive Guide

In the realm of industrial standards, precision, and quality are paramount. Among the numerous standards that govern various industries, DIN 16742 - TG5 stands out due to its specific relevance to tool holders and their critical role in ensuring the accuracy and efficiency of machining processes. This article aims to provide an in-depth look at DIN 16742 - TG5, its implications, and the significance it holds in manufacturing, particularly in the context of tool holders.