Overview
ISO 6004:1991 defines requirements for alpine ski binding screws used to mount bindings to alpine skis. This second edition (1991) replaces the 1981 edition and specifies dimensions, mechanical properties and fastening characteristics to make mounting more rational and safer. The standard standardizes drill diameters, penetration depths and torque values so manufacturers, installers and test labs can use consistent components and procedures.
Key topics and requirements
- Scope and designation: Applies to screws intended to provide axial preloaded assembly between binding and ski. Typical designation format: e.g., “Ski binding screw SBS 5.5 x 12 ISO 6004 – countersunk head.”
- Head and drive: Requires a cruciform (cross) drive No. 3; countersunk heads recommended for flush mounting (recommended countersink angle ~90°).
- Dimensions and thread: Examples in the standard include a nominal screw diameter of 5.5 mm; the screw’s threaded portion must extend to the head and exceed the specified penetration depth by at least 1 mm.
- Penetration and drilling: Fastening characteristics are based on a uniform drill diameter of 4.1 mm H12 and a recommended penetration depth in the range found in the standard (see clause on penetration).
- Mechanical properties:
- Minimum breaking torque: 10 N·m (for screws loaded about the axis).
- Maximum tightening (installation) torque: 3.3 N·m.
- Minimum stripping/torque-to-failure (moment of fouling): 5 N·m.
- Ductility requirement: screws must not fracture in ductility testing.
- Surface and corrosion protection: Screws must be coated or plated to provide corrosion resistance and a reproducible friction coefficient. The standard cites examples (e.g., electrolytic zinc with chromate passivation) and references ISO 4042 for coating requirements.
- Testing: Mechanical and application characteristics are verified using the methods specified in ISO 6005 and related referenced standards.
Applications and users
- Ski manufacturers: design reinforced mounting zones and specify drill patterns that match standardized screw penetration and drill diameters.
- Binding manufacturers and assemblers: select screws and tightening settings to meet torque and holding requirements for safe mounting.
- Service shops / technicians: use consistent driver settings and screws to avoid under- or over-tightening.
- Test labs and certifiers: assess screw performance, pull-out resistance and compliance with ISO 6004.
Related standards
- ISO 6005 - Ski binding screws: test methods
- ISO 4757 - Cross recess (Phillips) specifications
- ISO 4042 - Threaded components - coatings
- ISO 2702 - Mechanical properties for sheet-metal screws
- ISO 1478 - Sheet-metal screw threads
Keywords: ISO 6004, alpine ski screws, ski binding screws requirements, screw dimensions, torque specifications, drilling diameter, corrosion protection, ski mounting standards.
