IEC 61754-18:2001

Overview

IEC 61754-18:2001 specifies the standard interface dimensions for the type MT-RJ family of connectors. This IEC international standard defines plug, adaptor and receptacle interfaces for MT-RJ connectors, including versions with and without guide pins and with or without alignment ribs. The document sets geometric datums, ferrule sizes, pin/hole alignment features and tolerance grades to ensure mechanical interchangeability and reliable optical alignment.

Key Topics

• Connector family definition: The parent MT-RJ plug uses a rectangular ferrule (nominally 4.4 mm × 2.5 mm) aligned by two 0.7 mm diameter pins; it includes a single coupling latch, a spring-loaded ferrule and a male orientation key.
• Interface variants: Standardized interfaces include:
  • Plug without pins (single, 2-fibre 0.25 mm pitch, 2-fibre 0.75 mm pitch, 4-fibre 0.25 mm pitch)
  • Plug with guide pins (same fibre configurations)
  • Adaptor interface (for plug-adaptor-plug mating)
  • Receptacle interfaces with pins, with and without ribs (for plug-receptacle mating)
• Dimensional specifications and tolerances: Detailed dimensional tables and tolerance grades are provided for each interface. Critical dimensions (e.g., ferrule geometry, pin-hole sizes, plug gauge and gauge-pin geometry) are defined to achieve repeatable mating.
• Gauge and test criteria: The standard defines gauge-pin and plug-gauge geometries and acceptance criteria, including insertion depths and maximum insertion forces (e.g., gauge-pin insertion depth 5.5 mm with maximum force limits of 1.7 N for pin gauges and 3.4 N for plug gauges).
• Optical datum targets: Locations of optical datum targets relative to pin centres are specified to support consistent optical alignment across single- and multi-fibre variants.
• Intermateability: The standard lists compatible interface combinations (plug–adaptor–plug and plug–receptacle pairings) across the MT-RJ family.

Applications

• Useful for manufacturers of fibre optic connectors, adaptors and receptacles who need to design parts that mechanically intermate with MT-RJ products.
• Applied by cable assembly and termination businesses to ensure plug and receptacle compatibility and manufacturability.
• Relevant to test laboratories and quality teams for verifying mechanical conformance, gauge testing and tolerance checks.
• Adopted in telecommunications, local area network (LAN) hardware, data centers and any systems requiring compact multi-fibre rectangular ferrule connectors.

Related Standards

• Part of the IEC 61754 series covering fibre optic connector interfaces. Designers should consult other IEC 61754 parts for interfaces of different connector families and for cross-referencing intermateability with other connector types.

Keywords: type MT-RJ family of connectors, IEC 61754-18, MT-RJ interface dimensions, fibre optic connector interfaces.