It’s not news that Leonardo DaVinci was somewhat ahead of his time, and over the centuries many of the creations in his sketchbooks have been created and proved quite functional. The guys from the ...

Self-tapping screws are usually drilled into pre-made holes (pilot holes) in metals, such as zinc, aluminum, and bronze and its alloys, as well as plastics and resin-impregnated plywood. They create ...