ISO 12164-1:2023

Overview

ISO 12164-1:2023 defines the geometry and practical design rules for hollow taper shanks with flange contact surface (HSK) - the male part of the interface between cutting tools/adapters and machine tools (milling, drilling, turning, grinding). This second edition (2023) updates and expands the series by specifying five HSK shank types (A, AB, C, CB and EB) and improving balancing quality and provisions for automatic and manual tool change.

Key technical topics and requirements

• HSK shank types
  • Types A, AB, EB: feature a peripherally grooved flange for automatic tool change (AB is dynamically balanced; EB is symmetrically designed).
  • Types C, CB: have a flange without a peripheral groove and are intended for manual tool change (CB is dynamically balanced).
  • Type A/AB: can also be changed manually via radial access bore holes in the hollow taper.
• Dimensional specifications
  • Complete sets of parameters and size tables are provided for all HSK sizes (see Clause 4.5).
  • Tolerances: general tolerances per ISO 2768-1; cones per ISO 3040; form/orientation/run-out per ISO 1101.
• Dynamic balancing
  • HSK-AB and HSK-CB include balancing recesses and flange bore-hole locations and guidance for dynamic balancing according to ISO 16084.
  • Balancing measures are described for practical mass compensation (three recesses in the low taper groove, balancing bores at the flange, preferred balancing zones in Clause 5).
• Design and functional guidance
  • Clamping forces, material/heat treatment and design recommendations are covered (Clause 6 and informative Annex A).
  • Annex B covers medium-transfer units for shanks C/CB; Annex C provides an overview of shank types.

Practical applications and who uses this standard

• Machine tool manufacturers and integrators specifying tool interfaces and automatic tool-change systems.
• Cutting-tool, adapter and tool-holder manufacturers designing HSK shanks and balancing features.
• Tooling engineers and maintenance teams responsible for high-speed machining where dynamic balance and precise flange contact are critical.
• Metrology and quality departments verifying dimensional conformity and run-out of toolholders.
• OEMs specifying interface compatibility between spindles and toolholders.

Related standards (for implementers)

• ISO 16084 - balancing of rotating tools (referenced for dynamic balancing)
• ISO 2768-1 - general tolerances
• ISO 1101 - geometric tolerancing (form/orientation/location)
• ISO 3040 - cone dimensions and tolerances

Keywords: ISO 12164-1, HSK, hollow taper shank, HSK-AB, HSK-CB, tool holder, automatic tool change, dynamic balancing, machine tool interface.