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 in. with a 1/4 in. outside diameter shoulder, and a 7/16 in. 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 Sentry Supply part 650-7901 for screw sizes 6-8, Sentry Supply part 650-7902 for sizes 8-10, and Sentry Supply part 650-7903 for sizes 12-14, or Sentry Supply part 650-7904, which includes one of each one-way screw remover hand tools.