Dictionary
machine' screw"
a threaded fastener, either used with a nut or driven into a tapped hole, usually having a diameter of about ¼ in. (6.4 mm) or less and a slotted head for tightening by a screwdriver. Cf.
cap screw, machine bolt. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.