BigHead Bonding Fasteners Ltd. (Bournemouth, U.K.) has partnered with Caparo Vehicle Products (London, U.K.) to develop TwinDisk, a high-performance fastener for composite sandwich panels. The female system features two 316 stainless steel disks, each affixed to opposite ends of an internally threaded stainless steel collar or threaded stud by means of BigHead weld technology. A hole is drilled through the sandwich panel top skin, core is removed, BigHead’s two-part FS Acrylic adhesive is applied and the TwinDisk is pushed into the cavity where the bottom disk bonds to the bottom skin while the larger-diameter top disk adheres to the surface of the top skin, thus transferring tensile, shear and lateral loads to both skins. Studs are supplied with adjustable top heads, with fitting depths from 5 mm to 100+ mm (0.20 inches to 4.0+ inches). Threads are M4 to M16 (stud or collar). Stock head diameters are 20 mm, 30 mm and 40 mm (0.79 inch, 1.18 inches and 1.57 inches); other sizes can be supplied.