|University of Iowa Libraries||Lichtenberger Engineering Library|
X-Bracing: Any system of bracing in which the diagonals intersect.
Y: An arrangement of railroad tracks, resembling the letter Y, which is used for turning trains around. Sometimes spelled "Wye."
Y Level: A leveling instrument having its telescope in Y standards, permitting of a rotation therein and a removal therefrom with a reversal of ends, so as to facilitate the process of adjusting.
Yardage: The contents or amount of material expressed in cubic yards.
Yellow Ochre: A variety of ochre having a yellow color, used for paint.
Yield Point: That point, or intensity of stress, at which the rate of stretch begins to increase rapidly.
Yoke Riveter: A machine riveter in which the hammer is attached to one end of an elongated, narrow yoke and to the anvil at the other, the yoke permitting the reaching of rivets remote from the edge of the plates to be riveted.
Young's Modulus: Same as the "Modulus of Elasticity." -- The ratio of the direct stress per unit of area to the corresponding relative deformation, sometimes called Lineal Modulus. The numerical value is equal to the stress per unit of area in tension that would be required to double the length of a piece, were the material of which it is composed perfectly elastic.
Z-Bar: A rolled steel shape having a cross-section resembling the letter "Z" and all angles right angles.
Z-Bar Column: A fabricated column composed of four Z-bars and one web plate riveted together.
Z-Bar Iron: Iron rolled in the shape of a bar having a cross section resembling the letter Z, but with the web at right angles to the planes of the flanges.
Zigzag Riveting: Same as "Staggered Riveting." -- Rivets set in zigzag order, or so spaced that the rivets in one row are opposite the centres of the spaces of the adjoining rows.
Zinc White: An oxide of zinc, in the form of a white powder, which is used as a base for paint.