S-5! self-piercing screws, 1" (25 mm) long and 1/4" (6.3 mm) in diameter, with a 5/16" (8 mm) stainless steel capped hex head and a sealing washer. S-5! supplies this screw with many of its metal roof brackets and sells it separately in bags of 250 for replacement or additional attachment points.

S-5! installation instructions call for driving the screws with a screw gun fitted with a depth-sensing nose piece or an adjustable torque clutch. A slight compression extrusion of rubber around the washer is the visual check for correct seating; over-driving should be avoided.