Method for manufacturing a stack of supporting plates

Method for manufacturing a stack of supporting plates, wherein all of said plates are identical and have at least one flat side edge, and said plates in the stack are placed with the flat side edges in a common plane, said plates being made by pressing them out of a large plate;

• punching a central hole in each plate such that the central hole of each plate has a sloping edge formed therein which in the stack extends downwardly a distance beyond the lower surface of each plate and centers the plates in the stack;
• forming by punch means at least three indentations in each plate extending out of the plane of the plate, said indentations spaced-apart from each other and from the central hole;
• and rotating the punch means a fixed angular distance after each indentation forming to form angularly staggered sets of said at least three indentations in successively formed plates step, and stacking the formed plates whereby, after stacking, the indentations on a superjacent plate in the stack engage flat surface areas of a subjacent plate of the stack to thereby provide a non-nested stack of said formed plates.