A hinge assembly includes a hinge plate having a pin-receiving portion at a first end defining a passageway along the first end, and including a plurality of mounting holes. A pivot arm has a pin-receiving portion at a first end defining a passageway that is substantially coaxial with the passageway of the hinge plate. A hinge pin is disposed in the passageways to pivotally couple the pivot arm to the hinge plate. The pivot arm is pivotable between a closed position and an open position. The pivot arm includes a domed portion forming a cavity positioned to overlie one of the mounting holes in the hinge plate when the pivot arm is in the closed position.