ISO 4254-13:2023

Overview

ISO 4254-13:2023 - Agricultural machinery - Safety - Part 13: Large rotary mowers specifies safety requirements and verification methods for towed, semi‑mounted, or mounted large rotary mowers used in agriculture. It applies to machines with a cutting‑element tip circle of 1 000 mm or greater designed to shred crop residue, grass and small brush by impact. This part is intended to be used together with ISO 4254-1 (general safety for agricultural machinery) and focuses on hazards and mitigation specific to large rotary mowers.

Key topics and technical requirements

The standard covers both design requirements and test/verification procedures, including:

• Scope and definitions: machine types, cutting elements and excluded machines (e.g., rotary disc/drum mowers for forage, flail mowers, arm‑type and pedestrian mowers, lawn mowers covered by ISO 5395).
• Safety requirements and risk reduction: general design measures, guarding against thrown objects, prevention of inadvertent contact with cutting elements, guarding of rotating power components, attachment means for trailed/mounted configurations, and structural integrity.
• Verification and test methods: mandatory tests and conditions such as foot‑probe tests, cutting‑element impact tests, unbalance tests for cutting assemblies, structural integrity tests and thrown‑object tests (operator zone and scoring).
• Information for use: operator’s manual content, safe working practices and required markings/safety signs.
• Annexes and test aids: list of significant hazards (Annex A), test recording forms (Annex B), example mower illustrations (Annex C) and test details (e.g., corrugated fibreboard penetration tests in Annex D).

Where this Part differs from ISO 4254‑1, its provisions take precedence for machines designed to this Part.

Practical applications - who uses this standard

ISO 4254‑13 is essential for:

• Manufacturers and designers of large rotary mowers who must meet design, guarding and documentation requirements.
• Test laboratories and certification bodies performing impact, unbalance and thrown‑object testing.
• OEMs and agricultural equipment engineers integrating mowers with tractors or carrier machines.
• Safety managers, compliance officers and procurement teams assessing machine safety and conformity.
• Regulators and standardization bodies referencing harmonized test methods and acceptance criteria.

Compliance helps reduce operator risk, limit thrown‑object hazards, ensure structural integrity and provide clear user information.

Related standards (select)

• ISO 4254-1 - General safety for agricultural machinery (to be used together with ISO 4254‑13).
• ISO 4254-12 - Forage harvesting mowers (exclusions).
• ISO 5395 - Lawn mowers (exclusions).
• ISO 14982 - Electromagnetic compatibility for mobile agricultural machinery (EMC guidance, if applicable).

Keywords: ISO 4254-13, large rotary mowers, agricultural machinery safety, thrown-object test, cutting elements, verification, operator’s manual, safety requirements.