Tools Design and construction 30 Human engineering 22 Machines 10 Manufacturing industries 10 Computer input-output equipment 6 Engineering 6 Ergonomics 6 Machine 6 Sheet-metal work 6 Building 5 Carpentry 5 Dies (Metal-working) 5 Industrial engineering 4 Joinery 4 Machine-tools 4 Measuring instruments 4 Safety measures 4 Building trades 3 Composite materials 3 Materials 3 Materials science 3 . Equipment and supplies 2 CATIA (Computer file) 2 Carpenter's squares 2 Carpenters' squares 2 Cognition and culture 2 Computer programs 2 Engineering design 2 Equipment and supplies 2