ISO 12164-3:2023

Overview

ISO 12164-3:2023 defines the dimensions and key design features for hollow taper shanks with a flange contact surface (HSK) - the male part of the tool‑holder/spindle interface used on machine tools (milling, drilling, turning and grinding). This third edition specifies three HSK shank types (T, TA and U), dimensional tables, balancing zones, clamping guidance and design notes to ensure interchangeability and reliable interface performance.

Key topics and technical requirements

• Shank types and purpose
  • Type T: peripherally grooved flange for automatic tool change in turning machines (gripper for HSK‑T).
  • Type TA: peripherally grooved flange for automatic tool change in milling machines; designed to be usable for turning and compatible with grippers for HSK‑A/AB.
  • Type U: no peripheral groove - designed for manual tool change in turning machines.
  • T and TA can also be changed manually via radial access bore holes in the hollow taper.
• Dimensions and tolerancing
  • Complete dimensioning across nominal sizes (HSK‑25 to HSK‑160) is provided in Figure(s) and Table 1 of the standard.
  • Tolerances reference ISO 2768‑1 for general tolerances, ISO 3040 for cone dimensions and ISO 1101 for geometric tolerancing.
• Balancing
  • Preferred zones for static and dynamic balancing are specified to support high‑speed operation.
• Clamping forces and bending capacity
  • Guidance on required clamping force and its influence on bending moment capacity is provided (Annex A).
• Design, materials and accessory interfaces
  • Notes on HSK sizes, medium‑transfer unit mounting (see Annex B), and recommended materials/heat treatments are included.
• Designation and documentation
  • Rules for identifying shank types and sizes (designation) are given to ensure consistent procurement and manufacture.

Practical applications and users

• Who uses ISO 12164-3:2023
  • Machine tool manufacturers, tool‑holder and spindle designers, tooling suppliers, CAM planners, and quality engineers.
• Typical applications
  • Standardizing HSK shanks for automatic tool changers and manual tool change operations in turning, milling and grinding.
  • Specifying interfaces for high‑speed machining where balancing, clamping force and precise taper seating are critical.
  • Ensuring interchangeability of tool holders, medium‑transfer units and automation grippers across equipment from multiple vendors.

Related standards

• ISO 12164 series (other parts covering the HSK interface family)
• ISO 22402‑1 (medium‑transfer units)
• ISO 3040 (cone dimensions)
• ISO 2768‑1 (general tolerances)
• ISO 1101 (geometrical product specifications)

This standard is essential when specifying or manufacturing HSK hollow taper shanks (HSK‑T, HSK‑TA, HSK‑U) to ensure dimensional interchangeability, safe clamping performance and compatibility with automatic tool changers and machine spindles.