ISO 28927-11:2011

Overview

ISO 28927-11:2011 - "Hand-held portable power tools - Test methods for evaluation of vibration emission - Part 11: Stone hammers" specifies a laboratory, type-test method for measuring hand-transmitted vibration at the handles of stone hammers and engraving pens (tools used by stone masons). The standard defines how to obtain repeatable vibration emission values for comparison of different machine models under controlled laboratory conditions. It applies to pneumatically driven and other driven stone hammers but is not applicable to demolition hammers or chipping hammers intended primarily for use on metal or in construction.

Key topics and technical requirements

• Measurement scope: Vibration emission measured at the gripping areas (handles) of stone hammers while operating on stone workpieces.
• Type-test purpose: Results are intended to compare models of the same type of machine under laboratory conditions, representing representative upper-quartile values of typical use.
• Three-axis measurement & hand positions: Vibration is measured in three orthogonal axes and at both hand positions to capture total hand-transmitted vibration.
• Transducer placement: Transducers are positioned close to the operator’s hand (area between thumb and index finger) to minimize disturbance to grip and to reflect realistic exposure.
• Test conditions: Tools are tested while working on supported stone; the condition of inserted tools (chisels, bushes) and material support are critical for reproducibility.
• Instrumentation requirements: Includes specifications for mounting transducers, frequency-weighting filters, integration time, calibration and auxiliary equipment.
• Data reporting and uncertainty: The standard requires defined measurement procedures, reporting conventions (model test report in Annex A), and uncertainty determination (Annex B). Declaration and verification procedures reference EN 12096.
• Guidance for low magnitudes: For emission values below 2.5 m/s² the standard recommends using 2.5 m/s² as a conservative estimate for real working conditions, since field magnitudes can vary widely.

Practical applications and users

Who uses ISO 28927-11:

• Tool manufacturers - to design, test and compare stone hammers and engraving pens for vibration performance.
• Test laboratories - to perform standardized, repeatable vibration type tests and produce test reports.
• Safety and compliance teams - to support conformity assessment, product declarations and verification of vibration emission values.
• Procurement and specifiers - to compare models based on measured vibration metrics when selecting tools for stonemasonry tasks.

Practical benefits:

• Enables objective comparison of vibration emission between tool models.
• Helps manufacturers reduce hand-transmitted vibration through design improvements.
• Assists employers and health & safety professionals in selecting lower-vibration tools and estimating exposure.

Related standards

• ISO 20643 - Principles for evaluation of vibration emission (basis for ISO 28927 series)
• ISO 5349 - Measurement and evaluation of human exposure to hand-transmitted vibration
• EN 12096 - Declaration and verification of vibration emission values
• ISO 5391 / ISO 17066 - Vocabulary for pneumatic/hydraulic tools
• ISO 2787 - Performance tests for rotary and percussive pneumatic tools

Keywords: ISO 28927-11, stone hammers, hand-transmitted vibration, vibration emission, test method, type-test, engraving pens, transducer, three-axis measurement, vibration test code.