Metal expansion nuts, often referred to as expansion anchors or expansion inserts, are specialized fasteners that expand when a bolt or screw is threaded into them. They typically consist of a cylindrical body with slits along its length or an expandable design that facilitates outward expansion. The main purpose of these nuts is to create a secure grip within a substrate, such as concrete, wood, or metal, thereby preventing loosening due to vibrational forces, temperature fluctuations, or stress.

Brackets and connectors are specialized chipboard fixings that are designed to join chipboard sheets at right angles or to secure them to other materials such as concrete or steel. Brackets are typically made from metal and come in various sizes and shapes to accommodate different chipboard thicknesses and load requirements. Connectors, on the other hand, are mechanical fasteners that provide a strong and secure connection between chipboard sheets without the need for adhesives.