A fastener or fastening is a piece of hardware that mechanically connects or affixes two or more objects. Fasteners are typically used to create non-permanent joints, or joints that can be removed or dismantled without causing damage to the joining components.  Welding is one method of making permanent joints. Stainless steel, carbon steel, and alloy steel are the most common materials used to make steel fasteners.
Crimping, welding, soldering, brazing, taping, glueing, cement, or the use of other adhesives are some other methods of joining materials. Force can also be applied using magnets, vacuum (such as suction cups), or friction (like sticky pads). Some types of woodworking joints use separate internal reinforcements, such as dowels or biscuits, which can be considered fasteners within the context of the joint system, but are not general purpose fasteners on their own.