ISO 6519:2023

Overview

ISO 6519:2023 - Diesel engines - Fuel injection pumps - Tapers for shaft ends and hubs - specifies the dimensional and tolerance requirements for tapered shaft ends and mating hubs used on fuel injection pumps and high‑pressure supply pumps for diesel (compression‑ignition) engines. Published as the fifth edition in 2023, this ISO standard defines types of shaft ends and hub keyways to ensure reliable mechanical connection, interchangeability and correct assembly. The specified tapers may be used with or without keys and are also applicable to other equipment where no specific standard exists.

Key topics and requirements

• Scope: Dimensions and tolerances for tapered shaft ends and hubs for diesel fuel injection and high‑pressure supply pumps.
• Shaft end types: The standard contains multiple shaft end designs (notably types 1, 2 and 3), including options for threaded ends and manufacturing features (e.g., clamping collars).
• Hub keyways and cones: Keyway profiles, hub cone lengths and assembly requirements are specified so the mating faces and fixing nuts can be correctly engaged after assembly. For some key/slot details (type 3) the standard allows agreement between supplier and purchaser.
• Dimensions and tolerances: Detailed dimension tables and figures define nominal sizes, length limits and tolerance classes to ensure seating contact begins at the major diameter and that taper drive functions satisfactorily.
• Editorial notes: The 2023 edition supersedes ISO 6519:2015, adding shaft end specifications and correcting technical descriptions. The document contains no normative external references and lists ISO 3912 (Woodruff keys) in the bibliography.

Applications and users

Who benefits:

• Pump and engine manufacturers ensuring mechanical compatibility between pump shafts and engine drives.
• Design and mechanical engineers specifying mating parts, tolerances and assembly clearances.
• Production and quality control teams using the standard for inspection, gauges and acceptance criteria.
• Maintenance and repair professionals replacing pumps or designing retrofit couplings. Practical uses:
• Standardizing tapered shaft and hub dimensions for interchangeability across suppliers.
• Guiding machining and assembly of pump drive connections to minimize misalignment and ensure repeatable engagement.
• Defining keyway options and tolerance agreements for custom or legacy equipment.

Related standards

• ISO 3912 - Woodruff keys and keyways (referenced in the bibliography for key-related applications)

Keywords: ISO 6519:2023, diesel engines, fuel injection pumps, tapered shaft ends, hubs, tapers, dimensions, tolerances, keyways, pump shaft standards.