Abstract: The invention is directed to a device for rapidly attaching glass to a metal support structure without cracking the glass. The invention consists of a C clamp with a force providing screw threadably engaged through a hole in one leg of the C clamp. The force providing screw has a spindle on one end which rides in a channel in the metal support structure. A spring, Belleville washer or other energy storing device is mounted on the spindle and is compressed against the metal support structure by the spindle base when the force providing screw is tightened. The amount of force that can be applied is limited by the combination of the screw head on the force providing screw and the longer length of the channel in relation to the spindle.