Clamping devices and zero-point clamping devices for or on machine tools for holding workpieces to be processed; modular machine tools being parts of machines, namely, clamping machines, power chucks, steady rests, expanders, fixed or oscillating clamping bolts, double clamping bolts, and grid plates as parts of machines and in particular for fastening clamping devices; flanges being clamping cams; all the aforesaid goods being modular and being parts of machines; chucks being parts of machin...