ISO 24347:2019

Overview

ISO 24347:2019 specifies the dimensions, location and vertical loading for an 80 mm nominal diameter ball coupling device used to mechanically connect a towed, non-balanced implement to an agricultural towing vehicle. The standard ensures interchangeability and safe attachment by defining the ball, trailer shank, keeper arrangement, clearance zones and two design versions: close position and horizontal adjustable.

Key topics and technical requirements

• Ball coupling size and marking
  • Nominal ball diameter: 80 mm.
  • The coupling shall be permanently marked “80 mm”; the mating trailer connection must show a visible size identification.
• Geometry and keeper
  • Keeper-to-ball-centre distance: (65 ± 1) mm; keeper must be adjustable for wear.
  • Detailed ball and trailer shank dimensions and flange/weld options are provided (see Annex A).
• Articulation and clearance
  • Coupling must allow freedom of rotation with minimum articulation angles:
    • Yaw (A): ≥ 60° (some positions ≥ 90°)
    • Pitch (B): ≥ 20° (30° recommended)
    • Roll (C): ≥ 20°
  • Minimum clearance zones defined to avoid interference with PTO and driveline.
• Location relative to PTO
  • Ball mounted in the vertical plane of the vehicle longitudinal axis.
  • Upper location permitted only for the close position version.
  • Dimensional locations (T and V) given for close position and short/regular/extended horizontal positions.
    • Example values (close position): T = 50–250 mm; V min = 120 mm (PTO 1 & 2) or 145 mm (PTO 3 & 4).
    • Horizontal adjustable positions: short/regular/extended positions and V minima (see standard for full table).
• Vertical loading limits
  • Close position: maximum static vertical downward load = 40 kN.
  • Horizontal adjustable: tabulated depending on PTO type and ball position (e.g., PTO 1&2: short 27 kN, regular 18 kN, extended 13 kN; PTO 3&4: short 33 kN, regular 22 kN, extended 16 kN).
  • Upward loading (uploading) is not recommended.

Applications and users

ISO 24347:2019 is relevant for:

• Manufacturers of ball couplings, trailer shanks and tractor mounting assemblies.
• Tractor and implement designers ensuring mechanical compatibility and safe attachment.
• Test laboratories, certification bodies and conformity assessors verifying compliance.
• Fleet managers, service technicians and procurement specialists selecting interoperable coupling systems.
• Improves safety where PTOs and driveline clearance zones must be coordinated with towing connections.

Related standards

• ISO 500-1 / ISO 500-2 - PTO clearance zones and master shield requirements
• ISO 5673-2 - PTO drive shafts, PIC position and clearance

Keywords: ISO 24347:2019, ball coupling device 80 mm, agricultural vehicles, trailer shank dimensions, PTO clearance, vertical load limits, coupling keeper, close position, horizontal adjustable.