How do toolmaker clamps work?

Tool master clamps are quite easy to operate and operate.
	The center screw and outer screw must be turned counterclockwise to open the jaws.
	When the jaws are open wide enough, you can insert the workpiece.
	The jaws of the clamp are parallel, so if the opposite surfaces of your workpiece are flat, they should hold it securely in place.
	Once the workpiece is in place, the screws must be turned clockwise until they are hand-tight.
	A crowbar can then be inserted into the screw head hole and used to provide additional leverage when tightening.