adjustable parallels

adjustable parallels

[ə′jəs·tə·bəl ′par·ə‚lelz] (engineering) Wedge-shaped iron bars placed with the thin end of one on the thick end of the other, so that the top face of the upper and the bottom face of the lower remain parallel, but the distance between the two faces is adjustable; the bars can be locked in position by a screw to prevent shifting.