Overview
ISO 12164-6:2023 specifies the dimensions and design requirements for HSK receivers (hollow taper interface with flange contact surface) for machine tool spindles. It covers receivers of types AS, CS and ES that mate with HSK shanks defined in ISO 12164-5. The standard is intended for use on machine tools such as turning, drilling, milling and grinding equipment and defines geometry, tolerances and designation rules for HSK receivers to ensure interchangeability and reliable toolholding.
Key topics and technical requirements
- Receiver types
- AS - for automatic tool change (also can be changed manually).
- CS - for manual tool change via radial holes in receiver and shank.
- ES - for automatic tool change (manual change possible but less straightforward).
- Dimensions and sizes
- Detailed dimensions and tolerances are specified in Figures and Table 1 for nominal sizes 40, 50, 63, 80, 100, 125 and 160 (HSK types).
- Cones and form tolerances reference ISO 3040 and ISO 1101; general linear/angular tolerances reference ISO 2768-1 (tolerance class “m” when not otherwise specified).
- Material and heat treatment
- Receivers shall be made from tempering or case-hardening steel with a minimum core strength of 800 N/mm and a minimum surface hardness of 50 HRC after heat treatment and finish grinding.
- Clamping and torque transmission
- Annex A provides recommendations for clamping systems, required clamping forces and notes that the flange contact surface is decisive for torque capacity and stiffness.
- Example clamping forces (Table A.1): HSK 40 → 5 kN, HSK 50 → 6.8 kN, HSK 63 → 11 kN, HSK 80 → 18 kN, HSK 100 → 28 kN, HSK 125 → 45 kN, HSK 160 → 70 kN.
- Designation
- Standardized naming (e.g. Receiver ISO 12164-6 - HSK-AS 80).
Applications and users
- Who uses it:
- Machine tool OEMs, spindle and toolholder manufacturers, tooling suppliers, design and QA engineers, and maintenance teams.
- Practical uses:
- Design and manufacture of spindle receivers and toolholders to ensure interchangeability and safe torque transmission.
- Specifying tolerances and material/heat treatment for high-speed and precision machining.
- Selecting clamping systems and verifying clamping forces for automatic and manual tool change systems.
Related standards
- ISO 12164-5 - Shanks of types AS, CS and ES (mating shank dimensions)
- ISO 3040 - Dimensioning/tolerancing of cones
- ISO 1101 - Geometrical tolerancing (form, orientation, run-out)
- ISO 2768-1 - General tolerances (linear/angular)
Keywords: ISO 12164-6:2023, HSK receivers, hollow taper interface, HSK-AS, HSK-CS, HSK-ES, machine tool spindle, toolholding, clamping force, dimensions, tolerances.