Under the action of axial force, inner-outer sleeves keep close to axis and hub and produce frictional force, thus transfer torque and axial force and attain the goal of machine-running. Such a coupling possesses a number of majorities, such as strong load carrying ability, perfect centricity, easy assemble and disassemble, and long service-life. The SUPER LOCKS can be used in a lot of occasions, such as axis and gears, sprockets, pulleys, large-sized airfans and marine propellers. It's a product being widely popularized nowa-days.