ISO 9518:2018

Overview

ISO 9518:2018 - Forestry machinery - Portable chain-saws - Kickback test specifies a laboratory methodology to determine the kickback potential of portable chain-saws (gasoline and electric, including battery-powered) complete with guide bar and saw-chain. The standard defines how to produce a simulated kickback in a controlled kickback machine, measure the resulting rotary and horizontal energies, and compute the Computed Kickback Angle (CKA) using a prescribed computer program (Annex A). The 2018 edition extends the scope to electric-powered saws, tightens procedures for better reproducibility, and preserves validity of previous test results.

Key topics and technical requirements

• Scope limits: Intended for chain-saws up to 80 cm³ engine capacity and guide bar cutting lengths ≤ 63 cm.
• Test principle: A Medium Density Fibreboard (MDF) specimen is thrust into the moving saw‑chain at the bar tip to simulate kickback; the kickback machine measures peak horizontal and rotary energies.
• Specimen and material requirements:
  • MDF specimen sizes: 38×38×250 mm or 38×76×250 mm with rough side facing the bar tip.
  • Density: 737 kg/m³ ± 32 kg/m³.
  • Hardness: 2 892 N ± 667 N (hardness test method in Annex B).
• Chain‑saw configuration and families:
  • Test the worst‑case guide bar nose radius and highest‑energy saw‑chain.
  • Saws with engine displacements within ±20% and similar mass distribution may be treated as a family (test largest displacement at minimum).
• Measurements and instrumentation:
  • Mass, centre of gravity, polar moment of inertia (PMI - Annex D), bar/handle coordinates, engine speed, carriage velocity, and friction measurements (horizontal and rotary).
  • Chain brake energy, actuation angle and stopping time are measured for complete saw tests.
• Computation: Use the referenced computer program flowchart (Annex A) to compute CKA from measured inputs.

Practical applications and users

ISO 9518:2018 is useful for:

• Manufacturers of portable chain-saws validating design changes and comparing guide bars and saw-chains for kickback risk.
• Test laboratories and certification bodies performing conformity testing and safety evaluations.
• Product safety engineers and R&D teams assessing chain‑brake performance and kickback mitigation features.
• Procurement and compliance professionals requiring standardized kickback data for specifications and regulatory submissions.

Related standards

• ISO 6531 - Portable chain-saws - Vocabulary (terms and definitions referenced).
• ISO 6535 - Portable chain-saws - Chain brake performance.

Keywords: ISO 9518:2018, kickback test, portable chain-saws, chain-saw kickback, Computed Kickback Angle (CKA), MDF specimen, chain brake, guide bar, saw-chain.