Rotary type mechanical chuck is similar with spring type axial thrust mechanical chuck, they are both used to hold and grip 3 inch, 6 inch paper core for working.

Rotary type mechanical chuck working thoery:
When this chuck's side rotated a certain degree after pushing, its keys will expanded out and grip paper core tightly for rotating. After push force released, then its keys will go back again.

Rotary type mechanical chuck structure: