Solarfastener M10x70 with calotte for steel substructure

The K2 Solarfastener M10x70 with calotte is a self-drilling fastener for fixing K2 InsertionRail or SolidRail components through trapezoidal or corrugated steel sheet roofing into a steel substructure, without a separate adapter plate. It has a hardened drilling tip and a calotte (domed sealing washer) under the head, with an overall screw length of 85mm, made up of a 20mm shank and a 57mm steel thread section, with an 8mm drill-bit diameter, giving a clamping range of 18-60mm. It carries a European Technical Assessment (ETA). Made from stainless steel A2, it weighs 0.098kg and is supplied 25 to a box. K2 asks installers to submit top-chord width, profile height, clear width at the bottom chord and roof colour (RAL) with any order, and to complete K2's selection document for the calotte fastener. It appears, with its sibling lengths, in K2's hanger bolt and solar fastener length-calculation table and fastener overview.