Anchor bolt

Raw bolts/anchor bolts can be used to install/anchor heavy items like signage and metal brackets on a variety of walls made of different materials including concrete, brick, block and stone but aren't suitable when working with hollow brick. These  anchors work by way of expansion. You install into a pre-drilled hole (usually the same size as the anchor) you then tighten these anchors up and as you tighten them up an expansion point on the anchor will start to expand. As this happens, the bolt becomes tighter and tighter against the solid substrate ensuring a strong fit.