7 Machines and machine tools for treatment of materials and for manufacturing; die-tapping machines, die-cutting and tapping machines; milling machines; drilling machines; sawmills; welding machines; grinding machines; sharpening machines; cutting machines for the treatment of materials; cutting machines and apparatus, drilling machines and apparatus, grinding machines and grinding apparatus, sharpening machines and sharpening apparatus and surface treatment machines and surface treatment apparatus, conveyors, belts for conveyors, materials handling conveyors; devices and assemblies consisting of a clamping element for clamping unprocessed parts and workpieces