ISO 28927-2:2009

Overview

ISO 28927-2:2009 - Hand-held portable power tools - Test methods for evaluation of vibration emission - Part 2: Wrenches, nutrunners and screwdrivers specifies a laboratory, type-test method for measuring hand-transmitted vibration at the handles of powered fastening tools. The standard defines how to establish the magnitude of vibration in the gripping areas of impact, impulse, shut-off, ratchet or stall type machines (straight, pistol-grip, angle or bow handle) when tightening or loosening threaded fasteners. It is intended primarily to compare different models of the same tool type and covers drive outputs from 6.3 mm to 40 mm (1/4 in to 1 1/2 in). ISO 28927-2:2009 is focused on fastening tasks and excludes nutrunners designed solely for use with torque reaction arms.

Key topics and technical requirements

• Type-test laboratory method for measuring vibration emission at the tool handle during fastening operations.
• Measurement in three axes and at both hand positions to capture realistic hand-transmitted vibration.
• Transducer positioning guidance (primarily next to the hand between thumb and index finger) to reduce operator disturbance and improve reproducibility.
• Instrumentation requirements: transducer mounting, frequency weighting filters, integration time and calibration procedures.
• Test procedures: use of a brake/break-block test device for impact/impulse machines and free-running tests for other machines to provide consistent, repeatable loading.
• Reporting and verification: declared vibration emission values, uncertainty estimation and a model test report format.
• Limitations and interpretation: values are type-test averages (upper quartile representative); not a workplace exposure assessment. For workplace exposure use ISO 5349. ISO 28927-2 advises that emission values below 2.5 m/s² should not be used alone to estimate real working condition magnitudes.

Practical applications and users

ISO 28927-2:2009 is used by:

• Manufacturers and R&D teams to quantify and compare vibration emissions across product designs and to optimize ergonomics.
• Independent test laboratories performing type testing and certification of wrenches, nutrunners and screwdrivers.
• Procurement and safety professionals specifying tool acceptance criteria for workshops and industrial users.
• Ergonomists and occupational hygienists who need standardized bench data to inform risk assessments (with site-specific exposure measured per ISO 5349).
• Regulatory and conformity bodies verifying vendor-declared vibration emission values.

Related standards

• ISO 20643 - Principles for evaluation of vibration emission of hand-held machinery
• ISO 5349 - Measurement and evaluation of human exposure to hand-transmitted vibration
• EN 12096 - Declaration and verification of vibration emission values
• ISO 5391, ISO 691 - Vocabulary and tool tolerance references

Keywords: ISO 28927-2:2009, hand-held portable power tools, vibration emission, wrenches, nutrunners, screwdrivers, hand-transmitted vibration, test method, type-test, transducer positioning.