ISO 14275:2002

Overview

ISO 14275:2002 - "Aerospace - Drives, internal, offset cruciform, ribbed - Metric series" - specifies the dimensions and configurations for metric internal, offset cruciform, ribbed drives used in aerospace screws. It covers drives for metric screws with nominal thread diameters from 3 mm to 20 mm, defines dimensional tolerances in millimetres, and includes configuration drawings and tabulated dimensions for different head types.

Key topics

• Scope and dimensional data
  • Defines drive geometry for internal, offset cruciform, ribbed drives (metric series) for screws of 3–20 mm nominal thread diameter.
  • Dimensions, tolerances and location tolerances are given in millimetres; location tolerances conform to ISO 1101.
  • Configuration drawings (Figures 1–3) and detailed tables (Tables 1–3) specify per-size parameters.
• Head configurations
  • Includes provisions for drives in pan heads and 100° countersunk heads (normal and reduced).
  • Gauge penetration limits are provided for the different head types.
• Design and designation
  • Drive designation rules and parameter values for specified heads are defined, enabling consistent specification and procurement.
  • Notes on ribbing: ribs cover at least the lower 75% of the drive wall (per the standard’s table footnotes).
• Normative references and metrology
  • Cross-references to related aerospace fastener standards and tolerancing standards, including ISO 3202, ISO 5856, ISO 7913, ISO 13921.
  • Drivers and gauges used with these drives are defined in ISO 14277 and ISO 14278.
• Intellectual property
  • The standard notifies readers of a patent claim (Phillips Screw Company) covering internal ribbed drives (marketed as ACR or Torq-Set); licensing is addressed in the foreword.

Applications

• Use ISO 14275:2002 when specifying or manufacturing aerospace screws and mating tools to ensure interoperability, repeatable assembly, and compliance with aerospace fastener practices.
• Typical applications:
  • Aerospace fastener manufacturers and screw producers
  • Tool and driver manufacturers (designing internal offset cruciform drivers)
  • Quality assurance and inspection teams (using gauges and dimensional checks)
  • Procurement and engineering teams specifying fasteners and replacement parts
  • Maintenance and overhaul organizations requiring correct drive geometry for safe disassembly/assembly

Related standards

• ISO 14277 - Drivers, ribbed, for internal offset cruciform drives (metric)
• ISO 14278 - Gauges for internal offset cruciform drives (metric)
• ISO 3202, ISO 5856, ISO 13921 - Screw dimensions for various head types
• ISO 7913 - Tolerances of form and position
• ISO 1101 - Geometrical tolerancing (location tolerances)

Keywords: ISO 14275:2002, aerospace drives, internal offset cruciform, ribbed drive, metric series, metric screws, drive dimensions, Torq-Set, Phillips patent, drivers and gauges.