Expansion bolts, also known as wedge anchors, are a type of fastener used to secure materials to concrete, brick, or other masonry surfaces. They are commonly used in construction projects and for industrial applications. Expansion bolts work by inserting a bolt into a pre-drilled hole and then tightening a nut on the end of the bolt. As the nut is tightened, the end of the bolt is pulled towards the tapered end of the expansion sleeve, causing it to expand and grip the walls of the hole tightly. There are several types of expansion bolts available, including sleeve anchors, through bolts, and drop-in anchors. Sleeve anchors are the most common type and are ideal for medium to heavy-duty applications. Through bolts are used for heavier loads, while drop-in anchors are used for lighter loads. Expansion bolts are available in a range of materials, including zinc-plated steel, stainless steel, and hot-dip galvanized steel. The choice of material depends on the environment in which the bolts will be used and the level of corrosion resistance required. It is important to ensure that the hole is drilled to the correct size and depth for the expansion bolt to work effectively. Over-tightening the nut can cause the sleeve to split or damage the material being fastened. It is important to follow the manufacturer's recommendations for installation and use of expansion bolts to ensure a secure and safe fastening solution.