Scale. 1. A rule or measuring device having lines of division upon it. 2. Proportion of size.

Scarf. The bevel of a piece of metal that is to be lap welded.

Scraper. A hand tool that scrapes rather than cuts the metal.

Screw-cutting lathe. A lathe that has a screw feed with change gears to enable it to cut threads or screws upon the work.

Screw-cutting lathe with independent feed. A lathe that has a lead screw for cutting threads and a separate feed motion for ordinary tool traverse.

Screwing-machine. A machine used to cut screw threads.

Screw-machine. A form of lathe in which the spindle is hollow and a revolving head or turret is employed to carry the cutting tools.

Screw-plate. A tool for cutting external threads on small work.

Screw-thread. The thread upon a screw or other piece of work.

Screw-tool. Another name for a chaser.