General description ForgeFix TechFast Composite Panels to Steel Hex Screws are designed for joining composite panels to steel frame buildings. These screws feature a No.5 drill tip for self-drilling in heavy gauge steel up to 12.5mm and come with 16mm EPDM rubber washers to ensure a secure fit. They are engineered with a specially designed compression control thread to prevent damage and denting of the panels. Technical specifications Size: 5.5 x 150mm Insulation Thickness: 57-115mm Pack Size: 100 Drill Tip: No.5 Diameter: 5.5mm Length: 150mm Manufacturer Part Number: TFHW16CPSD55150H EAN: 5028485195252 Other information Fire and corrosion resistant, protected by Elementech corrosion resistant coating, salt spray tested to 1000 hours.