Two-jawed chuck. A chuck having two jaws.
U
Universal chuck. A chuck in which the jaws move simultaneously.
Universal joint. A joint or connection that permits a piece to be moved about in any required direction.
Universal milling-machine. A milling-machine that is capable of cutting spirals, and is provided with an index head.
Upright. A vertical post or frame.
U. S. standard thread. A V-shaped thread having a flat place at the top and bottom.
V
Vernier (vër′ni-er). A measuring device in which two sets of lines of division are employed, one set being narrower spaced than the other, but so spaced that in a certain number of divisions the two end lines of each piece measure exactly alike: this provides a means of making a minute measurement.
Vise. A work-holding device in which one jaw is movable and the other stationary.