ISO 28927-4:2010

ISO 28927-4:2010 - Overview

ISO 28927-4:2010 specifies a laboratory type-test method for measuring hand‑transmitted vibration at the handles of straight grinders. The standard defines how to mount a specified test wheel, run the machine under no‑load conditions, and record vibration at the gripping areas to establish a reproducible, comparable vibration emission value. It applies to hand‑held grinders (pneumatic or otherwise) using straight grinding wheels (type 1), tapered wheels (type 4) and cylindrical plugs (types 16, 18, 18R, 19). It is not applicable to grinders used with wire brushes or to die grinders with collet-mounted tools.

Key technical topics and requirements

• Type‑test laboratory procedure: Machine fitted with a prescribed test wheel and operated at no‑load free running speed to provide repeatable results.
• Measurement locations and axes: Vibration measured in three orthogonal axes at defined transducer positions near the user’s grip; measurements at both hand positions are included.
• Instrumentation: Requirements for transducer mounting, frequency‑weighting filters, integration time, auxiliary equipment and calibration to ensure valid results.
• Characterization and reporting: Methods to determine magnitude of vibration, combination of directional components, and the required content of the measurement report (model test report provided as an informative annex).
• Uncertainty and validation: Normative guidance for determining measurement uncertainty and criteria for validity of test runs.
• Corrections and limits: Machines with automatic unbalance‑reduction systems require a correction factor (1.3) to avoid underestimation. Emission values below 2.5 m/s² are treated cautiously; 2.5 m/s² is recommended as a practical floor when estimating real working vibration magnitudes.
• Test wheel definitions: Design and unbalance specifications for the test wheel are defined to improve reproducibility.

Practical applications and users

ISO 28927-4 is primarily used by:

• Tool manufacturers for type testing, product development and design verification of straight grinders.
• Independent test laboratories performing standardized vibration emission tests and issuing declarations.
• Compliance and certification bodies verifying declared vibration emission values.
• Occupational health professionals and purchasers comparing models for worker safety and procurement decisions. Note: For workplace exposure assessment, on‑site measurement and ISO 5349 (parts 1 & 2) are recommended because real‑world vibration can differ from type‑test values.

Related standards

• ISO 20643 - principles for evaluation of vibration emission of hand‑held machinery
• ISO 5349-1/2 - measurement and evaluation of human exposure to hand‑transmitted vibration
• EN 12096 - declaration and verification of vibration emission values
• ISO 603-12 and other referenced specifications for test wheels and components

This concise standard supports consistent, repeatable evaluation of vibration emission from straight grinders, enabling reliable model comparisons and safer tool selection. Keywords: ISO 28927-4:2010, straight grinders, vibration emission, hand‑transmitted vibration, test methods, type‑test.