PMJ-tec bi-metal stainless steel fasteners for composite panel roof systems 7550 6.3 x 2516 WasherColour matched 7571 5.5 x length19 WasherColour matched Application / Fastener range Substrate< 2 x 1.2mm1.2 – 3.5mm1.5 – 6.0mm4.0 – 12.5mm Panel / Rooflight fix 7571 75707575Profile stitch 7550