Plow bolts are a specialized type of fastener. These are similar to carriage bolts, but the head of a plow bolt is concave or flat. The underside of the head tapers down into a cone-shape which is engineered to fit into a countersunk recess. Countersunk recesses are designed to accommodate particular plow bolts. Many of the bolts have a square base, but some can have a key or a locking slot instead. They come in both metric and standard sizes. Hardened or heat-treated carbon steel and stainless steel are the most common materials used to make plow bolts.
