ISO 22402-1:2021

Overview

ISO 22402-1:2021 - "Medium-transfer units for tool interfaces - Part 1: Transfer units for hollow taper shanks in accordance with the ISO 12164 series" specifies the dimensional and functional requirements for medium-transfer units used to convey coolant or lubrication through hollow taper shanks. The standard covers transfer-unit types, dimensions, sealing and material requirements for both wet machining and Minimum Quantity Lubrication (MQL) applications. A corrected version was published in 2023.

Keywords: ISO 22402-1:2021, medium-transfer units, hollow taper shanks, ISO 12164, transfer units, wet machining, MQL, tool interfaces

Key Topics

• Scope and purpose: Defines dimensions and interface requirements for transfer units installed in hollow taper shanks as per the ISO 12164 series, enabling standardized coolant/lubricant supply through tool holders.
• Types and configurations: Multiple transfer-unit forms are specified (examples: Type A for wet machining; Types B–F for automatic tool change MQL; Types G–J for manual/tool-change variants). Figures and tables give detailed form and size options.
• Dimensional data: Nominal sizes and precise dimensions (including threaded sizes, lengths, radii and tolerances) are provided for compatibility with HSK and other taper interfaces.
• Sealing and pressure ratings:
  • Wet machining units must seal to at least 70 bar.
  • MQL automatic-tool-change units must seal to at least 10 bar.
  • Single-channel MQL systems are covered; 2‑channel systems require bespoke matching and are not detailed.
• Materials and heat treatment: Supply tubes shall be surface-hardened; wet machining supply tubes require a hardness of at least 56 HRC. O‑rings and sealing-element specifications are included.
• Functional requirements: Neutral centring, allowable angular movement, permissible displacement forces and tightening torques are specified to ensure reliable mechanical and fluid performance.
• Designation and documentation: Provides a standard designation format (e.g., "Transfer unit ISO 22402-1 - A - 50") and includes tables for O‑ring sizes and torque/force limits.

Applications

• Machine tool manufacturers: design and validate coolant/MQL feedthroughs for tool holders and spindle interfaces.
• Tooling and cutting-tool designers: integrate standardized transfer units into tool holders and adapters for consistent coolant delivery.
• Fixtures & assembly engineers: select correct transfer-unit types, O‑rings and fasteners to meet pressure and sealing requirements.
• Maintenance, procurement and QA: ensure interoperability, spare-part specification and compliance with ISO 12164-compatible holders. Practical uses include through-tool coolant supply, MQL delivery in single-channel systems, and ensuring interchangeability across HSK and related hollow-shank tool interfaces.

Related Standards

• ISO 12164 series - hollow taper shank/tool-holder interfaces (referenced throughout ISO 22402-1)
• Other parts of the ISO 22402 series - for additional transfer-unit types and guidance (see ISO website for the complete series)

For implementation, consult the full ISO 22402-1:2021 document for complete tables, figures and tolerances before design, procurement or manufacturing.