Breaking Torque Test

Breaking torque testing, also known as torque-to-failure is a critical mechanical test used to determine the point at which a component or assembly fails under rotational force. Unlike slip or retention torque tests that assess the torque required to initiate or sustain rotation, breaking torque tests identify the maximum torque a specimen can endure before irreversible damage occurs.

Typical failure modes include thread stripping, material fracture, or adhesive shear. These outcomes are key indicators of a product’s mechanical resilience, especially in safety-critical sectors. For example, torque-to-failure tests on orthopaedic screws ensure they can withstand the necessary surgical torque without breaking. In consumer goods such as toys, these tests confirm that small components like limbs or eyes remain securely attached under force, helping to avoid choking hazards.

Whether evaluating threaded closures, electrical connectors, or bonded joints, breaking torque testing provides engineers with valuable data on material performance under stress supporting both regulatory compliance and product safety.

Breaking torque testing is governed by a range of international and sector-specific standards that define testing protocols, equipment requirements, and performance thresholds.

ASTM D2061 – Zipper torque testing

Assesses the strength of zippers under torsional loading. Common in apparel and luggage testing, this standard helps identify design or material weaknesses that could lead to failure during use.

ASTM F543-13 and ISO 6475:1998 – Bone screws and implants

These standards define the mechanical testing requirements for metallic bone screws used in orthopaedic applications. They specify the methods for determining maximum torque prior to failure, ensuring screws remain reliable within the human body.

MIL-STD-750 and MIL-STD-202H – Electronic components

Military specifications used to test the mechanical robustness of semiconductor leads and terminals. They help confirm that components can endure mechanical handling and installation without detachment or fatigue.

BS EN ISO 8124 – Toy safety

This standard evaluates the torque resistance of components in toys. It ensures that parts subjected to rotational force during normal use or abuse do not detach and pose ingestion or inhalation risks to children.

These standards provide a consistent benchmark for safety and quality. While the torque requirements for a bone screw differ significantly from those of a semiconductor terminal, both must be tested against defined thresholds to ensure performance and compliance.

Applications across sectors

Breaking torque testing plays a central role in confirming that products are not only functional, but also durable and safe throughout their lifecycle.

In the medical sector, implants and surgical components must remain secure under operational loads. In consumer products, from toys to household appliances, components must resist detachment or failure. Even industrial items like screw-top containers benefit from validated torque resistance to ensure user safety and product integrity.

Supporting quality assurance processes

Torque-to-failure testing supports quality assurance by verifying material consistency, manufacturing repeatability, and supplier reliability. It is routinely used from product development through to end-of-line checks to validate design tolerances and production stability.

Routine testing helps detect batch inconsistencies, manufacturing faults, or process drift, while also supporting traceability and regulatory compliance particularly important in sectors such as aerospace and medical devices where oversight is rigorous.

Required equipment and setup

Mecmesin offers a range of torque testing systems suited to different torque capacities and application requirements:

• VortexPro: Ideal for mid-range torque applications. Its programmable controls are well suited to routine testing in quality control labs and production environments.
• HelixaPro: Designed for low-torque, high-precision testing, including delicate medical devices or micro-mechanical assemblies. Suitable for torque capacities from 0.05–1.5 Nm.
• Manual digital testers: Useful for spot checks, quick validations, or when portability is required.
• Fixturing: Correct fixturing such as mandrels, collets, or custom grips, is vital to prevent slippage and ensure consistent alignment of the sample during testing.

Accurate results depend on stable rotational speed, proper sample conditioning (e.g. temperature, humidity), and regular calibration of torque sensors to maintain audit readiness.

Best practices and common challenges

To improve reliability and reduce variability:

• Maintain a constant rotational speed to avoid introducing dynamic loads.
• Eliminate mechanical backlash to ensure consistent torque readings.
• Pre-condition materials when environmental sensitivity is a factor.
• Calibrate all torque measurement devices regularly and traceably.

By adhering to these best practices, engineers can ensure that test results are both repeatable and meaningful for real-world applications.

Mechanical torque testing continues to evolve alongside changes in manufacturing and material science. Key developments include:

• Miniaturisation and lightweighting: As components shrink, particularly in aerospace and electronics, torque testing must adapt to more sensitive ranges and finer resolutions.
• Traceability and compliance: In medical and defence applications, complete test traceability is increasingly required, including operator identification, timestamping, and compliance with electronic recordkeeping protocols such as CFR 21 Part 11.
• Software integration: Modern torque testers are often integrated with platforms like Mecmesin’s VectorPro software, which provides real-time data capture, automated pass/fail logic, and structured test reports.

New standards and methods are emerging to keep pace with these changes, ensuring torque testing remains relevant and rigorous across industries.

Mecmesin is a trusted provider of torque testing equipment for applications ranging from delicate electronics to industrial assemblies. Our solutions combine versatility, precision, and compliance support:

• Comprehensive torque range: From 0.05–40 Nm, covering low- to mid-torque applications.
• Custom fixturing: Our in-house engineering team designs bespoke fixtures tailored to irregular or complex component geometries.
• VectorPro software: Enables full control of test parameters, visualises torque profiles in real time, and supports secure data logging for traceability and audit compliance.
• Industry reputation: Mecmesin systems are widely used in sectors including medical devices, defence, electronics, and consumer goods.

Whether you're developing a prototype, verifying production parts, or meeting regulatory test requirements, Mecmesin delivers the expertise and tools required to perform accurate, repeatable breaking torque tests.

Need guidance on ASTM F543 or MIL-STD-202H compliance? Speak to our engineers about selecting the right breaking torque test equipment for your application. Book a demo to see VectorPro in action and find a tailored solution for your needs.