Overview
EN ISO 4566:1995 (ISO 4566:1992) specifies dimensions and tolerances for propeller shaft ends and propeller bosses (hubs) with a 1:10 taper intended for small craft with inboard engines. The standard covers shaft diameter ranges from 20 mm to 160 mm and establishes requirements to achieve mechanical interchangeability, correct fit and reliable transmission of propeller torque.
This edition reflects ISO/TC 188 work and replaces the earlier 1985 edition. It references related ISO documents for cone tolerances and key/keyway dimensions to ensure compatibility in manufacture and maintenance.
Key Topics
- Taper specification: 1:10 conical taper for shaft ends and corresponding boss bores.
- Shaft diameter range: Nominal diameters from 20 mm up to 160 mm are covered to provide a common interface for small craft propulsion components.
- Dimensions and tolerances: Detailed reference dimensions and tolerance bands are provided in the standard table to ensure interchangeability. Reference dimensions are nominal and intended for guidance.
- Threads and fastenings: Propeller nuts and shaft threads are specified to use M‑Fine threads as part of the assembly requirements.
- Keys and keyways: Key dimensions and tolerances follow ISO/R 773 (rectangular/square parallel keys) for consistent torque transmission.
- Cone tolerances: Cone diameter tolerances correspond to ISO 1947, linking taper accuracy and cone-angle tolerances to accepted international practices.
- Designation: Components manufactured to this standard are designated by the standard reference plus the nominal diameter (for example: Propeller boss ISO 4566 - 35).
Applications
EN ISO 4566:1995 is intended for designers, manufacturers, suppliers and maintenance teams working with small craft propulsion systems. Typical practical uses include:
- Designing propeller shafts and hubs for inboard-engined pleasure craft and small commercial boats.
- Manufacturing and quality control to ensure parts from different suppliers are interchangeable.
- Replacement and repair operations in shipyards and service facilities to confirm correct fit and safe torque transmission.
- Specifying procurement requirements for propulsion components in OEM and aftermarket contracts.
Adoption of the standard reduces the risk of misfit, improves safety margins in shaft-hub assemblies, and streamlines sourcing of compatible components.
Related Standards
- ISO 1947 - system of cone tolerances for conical workpieces (used for cone diameter tolerances).
- ISO/R 773 - rectangular and square parallel keys and keyway dimensions.
For complete manufacturing dimensions, tolerance tables and illustrative figures, consult the full text of EN ISO 4566:1995 / ISO 4566:1992.