Investment cast, Full Mortise hinges are 4.5” x 4.5" size with a mortise depth of 0.187”. These hinges can carry doors weighing up to 600 pounds. Includes Two concealed, maintenance-free bearings and Welded, Anti-ligature Hospital tip with reverse security stud. The Reverse Security Stud (RSS) 7/16” projection is a feature that has a welded stud projecting from the back of both leaves into the reinforcing plate of both the frame and the door. It is intended to keep the hinge locked in place from abuse of battering or trying to shear the hinge and screws. This feature is primarily used in prisons and psychiatric areas. Furnished with All Machine Security Torx screws - 1/4-20 x 1/2" Flat Head. ANSI A5111