A method of categorizing fasteners and construction connectors by size and type using a color coding system. Each fastener receives a designated and distinct color contained on the surface that is exposed before and after installation. The colors are preselected to define one or more physical properties...http://www.google.de/patents/US20040115022?utm_source=gb-gplus-sharePatent US20040115022 - Categorizing fasteners and construction connectors using visual identifiers
