ISO 6789-1:2017

Overview

ISO 6789-1:2017 - Assembly tools for screws and nuts - Hand torque tools - Part 1 defines minimum requirements for design conformance testing, quality conformance testing, marking and the declaration of conformance for hand torque tools used in controlled tightening of screws and nuts. The standard covers both indicating torque tools (Type I) and setting torque tools (Type II) and describes how manufacturers and test labs should verify tool performance and document conformity. Note: requirements for traceable calibration certificates are covered in ISO 6789‑2.

Key topics and technical requirements

• Scope and classification
  • Applies to Type I (indicating) and Type II (setting) hand torque tools and includes classes such as wrenches and screwdrivers (see annexes for examples).
• Design conformance testing
  • Tests and requirements applied during tool design or modification, including verification of maximum torque values, specified torque range, and scale/dial/display performance.
• Quality conformance testing
  • Production‑level checks to confirm manufactured tools meet design requirements.
• Torque measurement system and measurement requirements
  • Defines the torque measurement device and loading system used as the measurement standard, plus ambient condition considerations and measurement sequences.
• Performance tests
  • Includes maximum permissible deviation (accuracy concept), overload tests, endurance tests, and evaluation of effects from geometric changes.
• Measurement sequence and calculation
  • Procedures for applying torque, measuring output, and calculating deviation; worked examples and flowcharts are provided in the standard (Annex C).
• Documentation and marking
  • Minimum content for a declaration of conformance and required marking information for hand torque tools.

Practical applications and users

ISO 6789-1:2017 is used by:

• Tool designers and manufacturers to define and verify product performance and to prepare a declaration of conformance.
• Quality managers and production engineers for incoming inspection and production control of torque tools.
• Test and calibration laboratories performing design and quality conformance testing (note: for traceable calibration certificates, use ISO 6789‑2 and ISO/IEC 17025).
• Procurement and maintenance teams in industries requiring controlled tightening - automotive, aerospace, electronics assembly, industrial manufacturing, and service/repair operations.

Practical benefits:

• Ensures consistent performance of hand torque tools.
• Helps reduce assembly defects due to incorrect torque application.
• Provides a standardized basis for manufacturer claims and audit evidence.

Related standards

• ISO 6789-2:2017 - Calibration requirements and measurement uncertainty for hand torque tools.
• ISO 1173, ISO 1174-1 - Drive end and driving square dimensions for hand tools.
• ISO/IEC 17025 - Competence of testing and calibration laboratories.
• ISO 1703 (under revision) - reference numbers for tool identification.

Keywords: ISO 6789-1:2017, hand torque tools, design conformance testing, quality conformance testing, indicating torque tools, setting torque tools, declaration of conformance, torque measurement.