ISO 5718-2:2023

Overview - ISO 5718-2:2023 (Blades for Large Rotary Mowers)

ISO 5718-2:2023 is an international standard that sets material, testing and marking requirements for blades used on large rotary mowers (as defined in ISO 4254-13). It focuses on ensuring blade toughness and resistance to brittle failure when shredding crop residue, grass and small brush by impact under high centripetal forces. The document specifies test methods (Charpy impact and bend tests), acceptance criteria, sampling, marking and documentation for traceability. It does not set dimensional specifications.

Key topics and technical requirements

• Scope & exclusions: Applies to blades on large rotary mowers; excludes blades for rotary disc/drum and flail mowers for forage (ISO 4254-12), arm-type large rotary mowers, pedestrian-controlled motor mowers and lawn mowers (ISO 5395).
• Material requirement: Blade steel hardness shall be at least 38 HRC (Rockwell), per ISO 6508-1.
• Charpy impact test (ISO 148-1):
  • Test three specimens per heat of steel using X–Y orientation (ISO 3785).
  • Acceptance: average Charpy impact energy ≥ 20.3 J; failing lots must be rejected or re-treated and retested.
• Bend test:
  • Sampling: minimum one blade per 200, at least two per lot.
  • Test fixture and ram diameters defined by blade thickness (see Table 1 in standard).
  • Acceptance: no visible crack or break before reaching the required permanent set angle; alternate procedure targets 14.5% permanent surface elongation across the blade.
  • Corrective measures (anneal/reheat) require retest with doubled sample size for bend tests.
• Marking and documentation:
  • Each blade must be marked with manufacturer/trademark, lot/date/production run, and direction (if necessary).
  • Packaging should indicate the standard number “ISO 5718-2”.
  • Test performance and results must be documented for traceability.

Applications - who uses this standard

• Blade and agricultural implement manufacturers for product design, material selection and quality control.
• OEMs of large rotary mowers and attachment suppliers to ensure blade safety and performance.
• Third‑party testing laboratories and in-house QA labs performing Charpy and bend tests.
• Procurement, regulatory and compliance teams specifying durable, safety‑compliant cutting elements.
• Service and maintenance organizations assessing replacement blade conformity.

Related standards

• ISO 5718-1 (other cutting elements in the series)
• ISO 4254-13 (definition and safety of large rotary mowers)
• ISO 4254-12 (rotary disc/drum and flail mowers)
• ISO 148-1, ISO 3785, ISO 6508-1 (normative test methods referenced)
• ISO 5395 (lawn mower safety standards)

This standard is essential for ensuring the toughness, reliability and traceability of blades used in heavy-duty rotary mowing applications. Keywords: ISO 5718-2:2023, blades for large rotary mowers, Charpy impact test, bend test, Rockwell hardness, harvesting equipment, cutting elements.