These one-way shoulder screws are constructed of steel and come in a chrome-plated finish. They feature a tamper-proof head which prevents them from being loosened and removed Once installed. These fasteners are manufactured with #10-24 threads and have a reach of 15/16 inch, with a 1/4 inch outside diameter shoulder, and a 7/16 inch head diameter. One-way screws like these are commonly used with one-way barrel nuts in commercial restroom applications. The security drive heads of these fasteners allow for easy installation with a flat screwdriver, but require the use of a one-way screw remover tool. See item number 650-7901 for screw sizes 6-8, 651-0463 number 650-7902 for sizes 8-10, and 651-0463 number 650-7903 for sizes 12-14, or 651-0463 number 650-7904, which includes one of each one-way screw remover hand tools.