ISO 28927-12:2012

Overview

ISO 28927-12:2012 - Hand‑held portable power tools - Test methods for evaluation of vibration emission - Part 12: Die grinders specifies a laboratory, type‑test method to measure hand‑transmitted vibration at the handles of portable die grinders. The standard is intended to establish comparable vibration emission values between models used for deburring and light cleaning with collet‑mounted burrs, mounted points, flap wheels or cylindrical sleeves. It applies to pneumatic and other drive types, and emphasizes reproducible measurement under defined type‑test conditions.

Key topics and technical requirements

• Scope and applicability
  • Die grinders for deburring on materials from hard steel to plastics.
  • Also covers low‑speed grinders using flap wheels or cylindrical sleeves.
  • Excludes certain straight grinders and use with wire brushes (see ISO 28927-4 for straight grinders).
• Measurement approach
  • Laboratory, type‑test procedure for hand‑transmitted vibration emission at the gripping areas.
  • Uses a real grinding process to reflect typical use while improving reproducibility.
  • Results intended to represent the average upper quartile of typical vibration magnitudes.
• Instrumentation and positioning
  • Three‑axis vibration measurement is specified, with transducers positioned close to the hand (between thumb and index finger) to minimize interference with the grip.
  • Requirements for frequency weighting, integration time, transducer mounting and calibration are defined.
• Operating and test conditions
  • Detailed operating conditions, attached equipment (collets, burr types, holding fixtures), workpiece specification and operator requirements are prescribed.
  • Includes procedures for test validity, reporting and declaration of vibration emission values.
• Uncertainty and reporting
  • Annexes include a model test report and a normative method for determining measurement uncertainty.
• Key numerical guidance
  • The standard notes that emission values below 2.5 m/s² are not recommended for estimating real‑world exposure and suggests using 2.5 m/s² as a practical floor when necessary.

Practical applications - who uses ISO 28927-12:2012

• Manufacturers and R&D teams use it to type‑test die grinders and compare vibration performance across models.
• Test laboratories and certification bodies apply the method for reproducible vibration emission measurements.
• Health & safety professionals and ergonomists reference the values when evaluating tool design and potential hand‑arm vibration risks.
• Procurement and OEMs use declared vibration emission values to select lower‑vibration tools.
• Regulators and standards committees rely on the method for harmonized measurement and product claims.

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
• Other parts of ISO 28927 (e.g., Part 1, Part 4) for grinders and similar tools

Keywords: ISO 28927-12:2012, die grinders, vibration emission, hand‑transmitted vibration, type‑test, collet, deburring, measurement method.