Overview
ISO 8720:1991 specifies safety and performance requirements for original-equipment mechanical jacks supplied with passenger cars (as defined in ISO 3833). The standard ensures that vehicle jacks used for changing wheels and fitting snow chains are dimensionally suitable, safe in operation, durable, and stable under prescribed conditions.
Key topics and requirements
- Scope and applicability: Applies to mechanical jacks supplied as original equipment with passenger cars (see ISO 3833 for vehicle definition).
- Dimensional suitability: The jack must fit the vehicle jacking points and, with the vehicle at the manufacturer’s maximum total mass (see ISO 1176), lift the car sufficiently to replace the wheel with the spare (spare tyre inflated to maximum specified pressure).
- Operational effort limits:
- Up-and-down lever jacks: maximum 360 N
- Other jack types: maximum 120 N
- Accidental operation prevention: The jack mechanism must not move independently at any point in its travel when operating force is removed.
- Over-travel protection: Means shall be provided to prevent over-travel of the jack.
- Finish and safety: External surfaces protected against corrosion, moving parts lubricated, and no burrs, fins or sharp edges to reduce injury risk.
- Stability tests:
- With jack at upper limit, apply 250 N longitudinally (at 44 cm above road) and 250 N laterally at wheel midline; vehicle must not come off the jack.
- Repeat with vehicle loaded on specified slopes (gradient and camber defined) facing uphill and downhill.
- Durability test: 24 jacking cycles distributed around the jacking points with 5 minute intervals. After the test, operational effort limits must still be met and no undue wear or deformation permitted.
Applications and users
ISO 8720 is practical for:
- Vehicle manufacturers (OEMs) specifying or supplying mechanical jacks as original equipment.
- Automotive component suppliers designing jacks and mechanisms for passenger cars.
- Test laboratories and technical compliance teams performing safety, stability and durability assessments.
- Regulatory and type-approval authorities referencing jack safety in vehicle standards.
- Technical writers and maintenance teams preparing vehicle user manuals and safe-use instructions (written instructions are required by the standard).
Related standards
- ISO 3833:1977 - Road vehicles: vehicle types, terms and definitions (vehicle definition used by ISO 8720)
- ISO 1176:1990 - Road vehicles: masses - vocabulary and codes (used to define manufacturer’s total mass)
Keywords: ISO 8720, mechanical jacks, passenger cars, jack safety, jacking points, durability test, operational effort, OEM jack requirements.