Overview
ISO 10964:1993 is an international standard developed by the International Organization for Standardization (ISO) that specifies a test method for determining the torque strength of anaerobic adhesives on threaded fasteners. This standard focuses on evaluating the securing or locking effectiveness of anaerobic adhesives used in bolted assemblies by measuring the torque required to unscrew a nut and bolt bonded with adhesive.
The method is primarily designed for anaerobic adhesives but may also be applicable to other adhesive types if agreed upon by the testing parties. By quantifying parameters such as breakaway torque and prevailing torque, ISO 10964 assists in assessing the reliability and performance of adhesive-secured threaded fasteners.
Key Topics
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Scope of Testing
The test method evaluates the locking effect of anaerobic adhesives on threaded fasteners, determining torque values to break and overcome the adhesive bond between nuts and bolts.
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Torque Measurements Defined
- On Torque (TON): Maximum torque needed to screw the nut onto an adhesive-coated bolt.
- Breakaway Torque (TBA): Initial torque required to start unscrewing and break the bond in an unseated assembly.
- Breakloose Torque (TBL): Initial torque required to reduce or eliminate axial load in preloaded assemblies.
- Prevailing Torque (TP): Torque measured after bond breakage, usually at a 180° nut rotation.
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Test Apparatus and Conditions
Test setups include machines with graphic recording or direct reading torque wrenches. Fasteners are typically Ml 0 x 38 dimension, property class 8.8 bolts and nuts made from zinc-phosphated steel per ISO 898 standards. Specific environmental conditioning per ISO 291 ensures consistent results.
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Sample Preparation and Adhesive Application
Fasteners must be degreased, free of burrs or damage, and prepared in standard laboratory atmospheres. Adhesive is applied to bolt threads and nut surfaces covering an area equal to the nut height plus two threads.
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Test Procedure
Nuts are assembled to bolt under specified conditions (unseated or preloaded), and torque measurements are recorded while unscrewing at controlled speeds (2, 5, or 10 rpm). Data collected include breakaway, breakloose, and prevailing torques.
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Reporting Requirements
Comprehensive documentation includes adhesive identification, test conditions, equipment details, torque values, test speed, and specimen data to ensure reproducibility and traceability.
Applications
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Quality Control and Comparison
ISO 10964 is used by manufacturers and testing laboratories to compare the effectiveness of anaerobic adhesives in threaded assemblies, ensuring products meet required bonding strength and locking capabilities.
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Product Development and Specification Compliance
The standard supports R&D teams in optimizing adhesive formulations and fastener combinations for specific applications, aiding in certification against mechanical performance standards.
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Maintenance and Safety Assurance
By understanding adhesive torque strengths, engineers can specify appropriate bonding products to prevent loosening in critical machinery, automotive components, aerospace fasteners, and industrial assemblies.
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Flexible Use with Other Adhesives
While targeted at anaerobic adhesives, the method may be adapted for alternative adhesive types through mutual agreement, broadening its relevance in various bonding technologies.
Related Standards
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ISO 898-1:1988
Specifies mechanical properties of bolts, screws, and studs used for fastener test specimens in ISO 10964.
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ISO 898-2:1992
Defines mechanical properties for nuts, ensuring standardization of test components.
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ISO 291:1977
Provides standard atmospheres for conditioning plastics and adhesive test specimens, critical for consistent testing environments.
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Adhesive and Threaded Fastener Standards
Other ISO standards covering adhesive characterization, threaded fastener dimensions, and mechanical testing complement ISO 10964 for comprehensive bonding performance evaluation.
Keywords: ISO 10964, anaerobic adhesives, torque strength determination, threaded fasteners, adhesive bonding tests, breakaway torque, breakloose torque, prevailing torque, bolt and nut testing, adhesive locking effect, fastener testing standards, quality control adhesives.
Open preview (PDF)Adhesives — Determination of torque strength of anaerobic adhesives on threaded fasteners