Our Interscrews are comprised of a M5 captivated nut and screw. They are used for fixing windows and holding Aluminium frames onto the side of a cabin. The knurled nut press fits into the Perspex or frame to prevent it from turning and is not slotted to minimise tampering from the outside. Our 20mm machine screws are sold with either a 6mm or 10mm long M5 nut. Other sizes of machine screws are available with a MOQ.