The material of snap hook is usually divided into stainless steel, alloy steel or aluminum alloy. Steel hooks are hard and heavy, and are suitable for attaching anchor points or for contact with sharp metal equipment, such as safety harnesses and descenders. The breaking load of aluminum alloy shackles is not inferior to that of steel products. Aluminum safety hooks are relatively light in weight and are suitable for connecting various equipment of personal protective equipment and carrying multiple spares. However, aluminum alloy is less resistant to cutting, so avoid hooking with other sharp metals when using it.