HSK63F is a tool shank with a tapered interface that also features a 63 mm diameter at the large end, but with a taper angle of 45 degrees. It is a larger and heavy-duty interface compared to HSK63A and is used in high-performance and heavy-duty machine tools.

(Type A is for automatic tool changing, and Type C is for manual changing.) Types B and D are designed for high torque applications with moderate-to-high spindle speeds. (Type B is for automatic changing and Type D is for manual changing.)

The HSK 63 high-speed tool holders are made for use on precision CNC routers and machining centers, as well as point-to-point machines with automatic tool changers. The HSK tool holding system was developed in Germany as a set of standards and performance criteria for advanced machining where precision is imperative.

HSK is a German abbreviation, which translates to a hollow taper shank. A hollow taper means these tools holders don't have a retention knob and are creating for high-speed machining. These holders are becoming more popular in America due to their precision performance.