Overview
ISO 9757:2000 specifies the characteristics, dimensions and load requirements for threaded steel fork-ends used on aircraft control wire rope turnbarrels. Applicable to fork-ends made from either corrosion-resistant steel (Code A) or low-alloy steel (Code B), the standard defines geometry, marking, designation, material/surface-treatment options and normative technical references to ensure interchangeability and safety in aerospace control systems.
Key Topics and requirements
- Scope: Fork-ends for aircraft control cable turnbarrels (threaded, steel).
- Dimensions and loads: Detailed geometry, masses and minimum breaking loads are given in the standard’s Figure 1 and Table 1 - covering common MJ thread sizes (e.g., MJ4 through MJ12) and associated dimensional data.
- Materials:
- Code A - corrosion-resistant steels (see Annex A for national equivalence).
- Code B - low-alloy steels (see Annex A).
- Surface treatment:
- Corrosion-resistant steel: passivation (ISO 8074) or peening (annex A / SAE AMS reference).
- Low-alloy steel: cadmium plating (referenced in Annex A / EN or QQ-P-416 equivalents).
- Designation & marking: Standardized identity block and marking positions (manufacturer marking plus ISO-required ID); thread hand (R/L) indicated by code.
- Technical specification: Conformance with ISO 10955 for end fittings and turnbarrels; other normative references include ISO 2020‑1 (wire rope), ISO 5855‑2 (MJ threads), ISO 9761 (locking clips), ISO 13715 (drawing edges), and relevant EN/SAE/QC standards.
- Annex A: Normative correspondence table mapping ISO material and surface-treatment codes to European and U.S. national standards.
Applications and who uses it
ISO 9757 is intended for:
- Aerospace designers and stress engineers specifying control cable end fittings.
- Manufacturers and forgings shops producing threaded fork-ends for turnbarrels.
- Procurement and quality assurance teams verifying supplier conformity.
- Maintenance, repair and overhaul (MRO) organizations replacing or inspecting control-system hardware.
- Certification bodies and regulators assessing component traceability and compliance.
Typical applications include control cable turnbarrels, rigging assemblies and aircraft control systems where consistent thread dimensions, load ratings and corrosion protection are critical.
Related standards
Relevant cross-references included in ISO 9757:
- ISO 10955 - End fittings and turnbarrels for aircraft control wire rope (technical specification)
- ISO 2020-1 - Preformed flexible steel wire rope for aircraft controls
- ISO 5855-2 - MJ threads (limit dimensions)
- ISO 9761 - Locking clips for turnbuckles
- ISO 8074 - Surface treatment (passivation)
- EN and SAE standards listed in Annex A for material and plating equivalences
Keywords: ISO 9757, fork-ends, aircraft control wire rope, turnbarrels, aerospace standard, threaded fork-ends, dimensions and loads, corrosion-resistant steel, cadmium plating.