Metal Fasteners

Metal fasteners are of two kinds—those producing a permanent bond and those requiring either a releasable or a sliding bond. Screws, nuts and bolts, rivets, retaining rings and clamps are examples from the first category. Non-permanent fasteners include quick-release couplers and clamps intended for removal at a specified time and pins, which allow relative movement of fastened parts.
Metal fasteners must be strong to bear significant loads. In many cases, they can be manufactured by powder metallurgical or casting techniques. Iron is a constituent of many types of metal fasteners, although titanium increasingly is coming into use in applications where strength must be balanced against a lightweight. In most applications where permanent bonding is required metal fasteners are replaceable by some form of welding or soldering.