Overview
ISO 4566:1992 specifies dimensions and tolerances for propeller shaft ends and propeller hubs intended for small craft with inboard engines. The standard covers shaft diameters from 20 mm to 160 mm with a taper of 1:10, and establishes requirements to ensure mechanical interchangeability between shafts and hubs used in pleasure craft.
The document focuses on practical features that affect fit and serviceability: conical shaft and hub geometry, key/keyway arrangements, thread geometry for propeller nuts, and the dimensional data given in Table 1.
Key Topics
- Scope and applicability: Standardized interchangeability for shaft diameters in the 20–160 mm range with 1:10 taper for small craft.
- Conical geometry: Defines the 1:10 taper for shaft ends and matching hubs to ensure accurate seating and torque transmission while allowing disassembly.
- Dimensions and tolerances: Detailed dimensional data are provided in Table 1 of the standard. Nominal diameters without parentheses are preferred; values in parentheses are alternatives.
- Key (clavette) and keyway: Key dimensions and tolerances follow ISO/R 773 (parallel square or rectangular keys). The specification leaves certain manufacturing details (keyway radii, fillets, reliefs) to the designer provided interchangeability is maintained.
- Thread requirements: Propeller nuts and shaft ends use metric fine threads. The length of the thread is required to equal the thread diameter, and the portion of thread engaged by the nut must be at least 80% of the thread length.
- Designation and marking: Components conforming to ISO 4566 should be designated by the standard reference and nominal diameter (example: "Moyeu d’hélice ISO 4566 - 35").
Applications
- Marine propeller couplings on small inboard-engine pleasure craft
- Replacement and aftermarket propeller hubs and shafts where interchangeability is essential
- Shipyard and repair facility standardization to reduce downtime and stock variance
- Design reference for manufacturers producing shafts, hubs, keys and propeller nuts
Related Standards
- ISO/R 773 - Clavette (parallel key) dimensions and tolerances (referenced for key/keyway tolerances)
- ISO 1947 - Taper tolerance system for conical parts (taper tolerance guidance)
By applying ISO 4566:1992, designers and manufacturers achieve consistent fit, reliable torque transmission and simplified maintenance procedures for propeller shaft assemblies on small craft. For exact dimensional values and manufacturing tolerances, consult Table 1 and the normative references within the standard.