CUTTING TOOLS, NAMELY, CUT-OFF TOOLS FOR CUTTING METALS, AND REPLACEMENT INSERTS THEREFOR; GROOVING TOOLS FOR GROOVING METALS AND REPLACEMENT INSERTS THEREFOR; THREADING TOOLS NAMELY FOR THREAD MILLING CUTTERS, TAPS AND DIES AND REPLACEMENT INSERTS THEREFOR; CUTTING INSERTS FOR MACHINE TOOLS; AND TOOLS HOLDERS FOR POWER OPERATED CUTTING, GROOVING AND THREADING INSERTS