ISO 5674:2004

Overview

ISO 5674:2004 - “Tractors and machinery for agriculture and forestry - Guards for power take-off (PTO) drive-shafts - Strength and wear tests and acceptance criteria” - defines laboratory procedures to assess the strength and wear resistance of guards for PTO drive-shafts used on agricultural and forestry tractors and implements. Designed to be used in combination with ISO 5673, the standard sets test equipment, environmental conditions, test sequences and acceptance criteria for PTO guards and their restraining means (excluding guards intended as steps or guards limited by national rules).

Key topics and technical requirements

• Test scope and setup
  • Guards must be representative production models and tested with intended PTO drive-shafts (typical closed length 900–1 010 mm).
  • Tests follow a prescribed sequence (Annex A) and must respect manufacturer installation and restraining systems.
• Operational parameters
  • Shaft rotational speed for dynamic tests: 1 000 r/min.
  • Measuring tolerances defined (e.g., rotational speed ±0.5% +5%, temperature ±1.0 °C ±5%).
• Wear testing
  • Cyclic operation between extended and closed shaft lengths while revolving; repeated temperature and dust exposure phases (examples in the standard: 85 °C cycles, ambient temperature, and dust atmosphere at 0.5 kg/m³).
  • Running torque checks before/after wear cycles (limit: ≤ 2.5 N·m per bearing race, up to 10 N·m per complete driveline).
• Corrosion and environmental exposure
  • Bearing corrosion test using salt solution (50 g/L NaCl) applied in repeated cycles when bearings contact the shaft.
  • UV degradation guidance and a UV test for plastic guards are provided (Annex B) where applicable.
• Strength tests
  • Dynamic radial loading, joint-covering load tests and tube mid-span loading using specified loads (e.g., 500 N applied for 60 s with defined support/backing).
  • Tests at sub-zero temperatures are included for low-temperature performance assessment.
• Acceptance criteria
  • Guard passes if there are no holes or deformations that leave the shaft unprotected, and no breakage, crack or part separation that compromises protection.

Applications and users

• Manufacturers of tractors, PTO drive-shafts and safety guards - for design validation and production verification.
• Third‑party test laboratories and certification bodies - for compliance testing and issuing conformity evidence.
• OEMs, safety engineers and procurement teams - to specify robust guard designs and ensure field durability under dust, temperature and corrosion stresses.
• Regulators and standards committees - to harmonize safety testing and acceptance criteria for agricultural and forestry machinery.

Related standards

• ISO 5673 series (PTO drive-shaft general and safety requirements)
• ISO 500 (rear-mounted PTO types)
• ISO 4892-1 / ISO 4892-2 (plastics weathering tests)
• ISO 105‑A02 (colour fastness grey scale)

Keywords: ISO 5674:2004, PTO guards, power take-off drive-shafts, wear test, strength test, tractors, agricultural machinery, acceptance criteria.