Abstract: In a shear machine, the lower or fixed knife which is installed in a bed or table, which, in turn, is slidably supported on the front sloping edges of the machine housings, is adjustable horizontally with respect to the upper or movable knife by a power actuated wedge assembly installed frontally, in position to elevate the bed or table along the sloping edges, to reduce the horizontal spacing between the knives. Adjustable horizontal increase of the spacing between the knives is accomplished by adjustably lowering the bed or table along the sloping edges of the side wall housings, utilizing power in cooperation with the pull of gravity to accomplish this.