20 Pipe clamps, not of metal; non-metal clamps; pipe clamps of plastics; pipe clamps of rubber; hose clamps, not of metal; cable clamps, not of metal; pipe clips of plastics; clips, not of metal, for cables and pipes; non-metal clips for general use; plastic cover for metal hose clamps; water-pipe valves of plastic; collars, not of metal, for fastening pipes; pipe collars, not of metal; non-metal fastener nuts; non-metal fastener screws; non-metal fastener bolts; rivets, not of metal; washers of plastic for commercial or industrial use; non-metal binding screws for cables; hangers for securing pipes and hoses, not of metal; hose hangers, not of metal