PMJ-tec bi-metal stainless steel fasteners for standing seam roof systems 7510 5.5 x 3816 Washer 7510 5.5 x 2516 Washer 7517 6.3 x 4716 Washer 7510 5.5 x 2516 Washer Application / Fastener range Substrate1.2 – 3.5mm1.5 – 6.0mm4.0 – 12.5mm Liner/Top hat fix 7510 75207530Halter fix 7510751775207530