Mechanical chuck and safety chuck are used for roller wind and unwind, but their working situation, appearance and model are different. For the mechanical chuck, it has spring and rotary two types, and safety chuck has sliding, tilting, foot mounted and flange mounted four types. 

As usually, safety chuck is matched with air expanding shaft for winding and unwinding. And the mechanical chuck doesn't need air shaft, it is matched with hydraulic loading device, without air shaft winding and unwinding is available.

Mechanical Chuck

Safety Chuck