Punch. A small tool to be struck by a hammer in order to make an impression or indentation.
Quadrant plate. A plate on which are placed lines and numbers indicating degrees.
Quadruplex. A term to designate that system of telegraphy in which four messages are sent over a single wire at the same time.
Ratchet. A wheel having teeth at certain intervals to catch the end of a pawl or finger.
Ratchet brace. A tool to hold a drill, having a reversible ratchet wheel.
Rasp cut. A cut of a file which is rough, not smooth.
Rake. The angle or inclination of the upper surface of the cutting tool of a lathe.
Reverse. To turn about; in the opposite direction.
Revolve. To move in an orbit or circle, as a merry-go-round.
Reciprocity. To give back in like measure.
Reflection. The throwing back from a surface.
Resonance. The quality of vibration which adds to the original movement, and aids in perpetuating the sound.
Refraction. The quality of light which causes it to bend in passing through different substances.
Reducing. Bringing it down to a smaller compass.
Retort. A furnace of refractory material to take high heat.
Reamer. A tool designed to enlarge or to smooth out holes.
Regulation. To do things in an orderly way; a system which sets forth certain requirements.
Refractory. Difficult to work, and not easily fused.
Rocking. A lever which rotates only part way and then moves in the opposite direction.
Rotate. A spindle which turns round. Compare revolve.
Rosin. Certain gums; particularly the sap of pine trees.
Roughing. The taking off of the first coating with a tool.
Saturated. A soluble substance which cannot be further dissolved by a liquid.
Screw plate. A tool which has within it means for adjusting different cutting tools.
Section lining. The marks made diagonally across drawings to indicate that the part is cut away.
Shaper. A large tool for surfacing off material, cutting grooves, and the like.
Shrinkage. The term applied to metals when cast, as all will be smaller when cold than when cast in the mold.
Slide rest. The part of the lathe which holds the tool post.
Sonorous. Having the quality of vibration.
Solvent. That which can be changed from a solid by liquids.
Spelter. A combination of zinc and copper. A hard solder.