ISO 28927-1:2019

Overview - ISO 28927-1:2019 (Angle and vertical grinders)

ISO 28927-1:2019 defines a laboratory type‑test method for measuring hand‑transmitted vibration emission from hand‑held portable power tools - specifically angle and vertical grinders. The standard specifies how to measure vibration at the tool handles using a specified test wheel under no‑load conditions. It is intended to produce reproducible, comparable vibration emission values for surface grinding tasks (cutting and sanding generally produce lower vibrations) so manufacturers, test labs and compliance bodies can evaluate and compare models.

Key technical topics and requirements

• Scope and applicability: Applies to hand‑held angle and vertical grinders driven pneumatically or by other means, intended for grinding, cutting‑off and rough sanding; excludes die grinders and straight grinders.
• Type‑test method: Laboratory procedure using a geometrically defined test wheel with controlled unbalance to simulate typical surface grinding vibration.
• Measurement location: Transducers are positioned at the gripping area (principally between thumb and index finger) to minimize operator disturbance.
• Instrumentation and calibration: Requirements for accelerometers/transducers, mounting, frequency weighting, integration time and calibration to ensure traceable results.
• Operating conditions: Specifies machine drive conditions (pneumatic, hydraulic, electrical), attached equipment, feed force and test procedure under no‑load.
• Data reporting and validation: Defines reported vibration values, declaration/verification procedures, correction factors and measurement uncertainty (Annex B).
• Correction factors: Applies a factor of 1.3 for machines with automatic unbalance reduction and 1.6 for grinders used with cupped wire brushes.
• Practical guidance: Advises that measured emission values below 2.5 m/s² should not be used directly to estimate real‑world exposure and recommends using 2.5 m/s² as a conservative estimate when necessary.
• Annexes: Includes a model test report (Annex A), uncertainty determination (Annex B) and test wheel design (Annex C).

Practical applications and users

• Manufacturers of angle and vertical grinders for design validation and product comparison.
• Independent test laboratories conducting vibration type‑tests and conformity assessments.
• Health & safety professionals and ergonomists assessing vibration risks and providing guidance on tool selection.
• Regulators and conformity bodies verifying declared vibration emission values.

Related standards (normative references)

• ISO 20643 - Principles for evaluation of vibration emission
• ISO 5349 - Measurement and evaluation of human exposure to hand‑transmitted vibration
• EN 12096 - Declaration and verification of vibration emission values
• ISO 2787, ISO 5391, ISO 17066 - complementary tool and vocabulary standards

Keywords: ISO 28927-1:2019, vibration emission, hand‑transmitted vibration, angle grinders, vertical grinders, test methods, type‑test, test wheel, tool vibration measurement.