Overview
ISO 1965:1973 specifies the characteristics and requirements for aluminium terminal ends for crimping to aircraft aluminium electrical cables. It applies where stabilized conductor temperatures do not exceed 105 °C. First published in 1973 by ISO/TC 20 (Aircraft and space vehicles), the standard defines terminology, materials, dimensional limits, finish, corrosion inhibitors, inspection, markings, performance and installation guidance for reliable aircraft crimp terminations.
Key Topics and Requirements
- Scope & terminology: Terminology is aligned with ISO 1966 (Crimped joints for aircraft electrical cables).
- Materials: Terminal ends must be made from aluminium or aluminium alloy.
- Dimensions: A tabulated set of dimensional requirements defines palm, barrel and clearance sizes; notable rules include:
- Palm width = between 2.25 and 3 times the nominal stud diameter.
- Minimum palm cross-sectional area must carry the full rated current of the cable.
- Maximum section of a crimped barrel must not exceed the palm width.
- Finish & plating:
- Palm surfaces must be flat and parallel within 0.1 mm total indicator reading before plating.
- Terminal ends shall be tin plated to the satisfaction of the approving authority.
- Inhibitors & sealing: Manufacturer must fill terminals with an inhibiting compound and seal them for transit/storage to prevent moisture ingress and re-oxidation after crimping.
- Inspection & markings:
- Parts inspected against approved drawings and must be free of harmful defects.
- Markings must include “AL”, cable size (e.g., AL/2) and manufacturer ID; markings must not be on the contact area or deformable crimping barrel.
- Performance & installation:
- Crimped terminals shall meet performance requirements of ISO 1966.
- Recommended contact pressure: 5.5–8.3 MN/m² (800–1,200 lbf/in²).
- Fasteners: studs/bolts should meet recommended tensile strength (~510 MN/m²) and thermal expansion properties (≈16×10⁻⁶/°C). Use load-bearing cadmium‑plated washers and stiffnuts or locking washers as specified.
Applications and Users
ISO 1965:1973 is intended for:
- Aircraft wiring harness designers and OEMs specifying aluminium lug characteristics.
- Cable assembly manufacturers and aerospace crimping operations.
- Maintenance and repair organizations establishing repair or replacement practices.
- Quality assurance, inspection and procurement teams ensuring parts meet aerospace requirements.
Use cases include specifying terminal ends for aluminium conductor installations, establishing inspection criteria, preventing galvanic corrosion and ensuring electrical continuity and mechanical integrity in aircraft systems.
Related Standards
- ISO 1966 - Crimped joints for aircraft electrical cables (referenced for terminology and performance requirements).
Keywords: ISO 1965:1973, aluminium terminal ends, crimping, aircraft aluminium electrical cables, crimped joints, tin plating, inhibitors, aerospace wiring standards.
