TOOLING MATE | BIG DAISHOWA SEIKI CO., LTD.,BIG DAISHOWA-Americas - HSK Tooling System HSK is a German acronym that means hollow taper shank and serves as the hollow taper interface that connects to HSK machines using flange contact. Materials,HSK-F63-MEGA32D-105A | BIG KAISER,HSK-A63-MEGA25D-100A | BIG KAISER