What is HSK tool holder
HSK tool holder is the best tool for high-speed cutting applications, and has become an important part of machining and manufacturing technology in high-speed cutting. After several revisions, the International Organization for Standardization issued the official ISO standard ISO12164 for the HSK tool system in 2001.
At present, the HSK (German Hohl Shaft Kegel abbreviation) tool system in Germany, the KM tool system in the United States, the NC5 and BIG-PLUS tool systems in Japan, etc., are widely used in high-speed cutting.

Introduction of HSK tool holder
High-speed machining has become an important part of machining manufacturing technology. The machining performance of the traditional BT tool system has been difficult to meet the requirements of high-speed cutting.
The tool system can perform cutting at high speed, and the following basic conditions should be met:

1. High system accuracy
The system accuracy includes the system positioning and clamping accuracy and the tool repeatability positioning accuracy. The former refers to the connection accuracy between the tool and the tool holder, and the tool holder and the machine tool spindle; the latter refers to the consistency of the tool system accuracy after each tool change. The tool system must have high system accuracy to ensure the static and dynamic stability of the tool system under high-speed machining conditions.

2. Higher system stiffness
The static and dynamic stiffness of the tool system is an important factor affecting the machining accuracy and cutting performance. Insufficient rigidity of the tool system will cause the tool system to vibrate, thereby reducing the machining accuracy, increasing the wear of the tool, and reducing the service life of the tool.

3. Better dynamic balance
Under the conditions of high-speed cutting, the unbalance of the small mass will cause huge centrifugal force, which will cause the sharp vibration of the machine tool during the machining process. Therefore, the dynamic balance of the high-speed tool system is very important.

Formulation of HSK Tool System Standards
    Since 1987, a special working group has been established by the machine tool laboratory of Achen University of Technology in Germany, as well as some tool manufacturers, machine tool manufacturers, user enterprises and other more than 30 units. Under the leadership of Professor M. Research and development work. After the first round of research, in July 1990, the working group submitted a standard proposal for "Automatic Tool Change Hollow Shank" to the German Industrial Standards Organization. Germany published the draft DIN standard for HSK tool system in July 1991, and suggested to the International Organization for Standardization to develop relevant ISO standards. In May 1992, the International Organization for Standardization ISOT/TC29 (Tool Technical Committee) decided not to formulate the ISO standard for automatic tool change hollow shanks. After the second round of research by the working group, Germany formulated the official industrial standard DIN69893 for the HSK tool system in 1993. In May 1996, at the ISO/TC29/WG33 review meeting, the HSK tool system based on DIN69893 was formulated. Draft ISO standard ISO/DIS12164. After several revisions, the official ISO standard ISO12164 for HSK tool systems was promulgated in 2001.