Screw be an appropriate choice. The left side pedal of a bicycle has a left-hand thread. More generally, screw may mean any helical device, such as a clamp, a micrometer, a ship's propeller, or an Archimedes' screw water pump. There is no universally accepted distinction between a screw and a bolt. A simple distinction that is often true, although not always, is that a bolt passes through a substrate and takes a nut on the other side, whereas a screw takes no nut because it threads directly into the substrate (a screw "screws into something", a bolt "bolts several things together").
Archimedes (CAD) Archimedes (CAD) Archimedes – "The Open CAD" – (also called Arquimedes) is a computer-aided design (CAD) program being developed with direct input from architects and architecture firms. With this design philosophy, the developers hope to create software better suited for architecture than the currently widely used AutoCAD, and other available CAD software. The program is free software released under the Eclipse Public License. Archimedes uses its own XML-based open format, which resembles SVG. It does not yet include support for other , but DXF support is planned. Archimedes is written in Java, and the latest version runs on Windows, Mac