Mechanical Pins are devices used to hold to objects or materials together.  They work by being inserted into a hole, which would prevent the movement of the objects to move perpendicular to the shaft of the mechanical pins. They are most effective by countering a sheer force, which is applied between the two materials or objects. They can be used to keep objects in particularly designed locations and prevent them from moving or slipping out of a desired position.

Mechanical pins can vary in diameter, material type, coating type, and whether they are solid or tubular. Each of these characteristics adds to their sheer strength and effectiveness and often determines their appropriate application and use.

Mechanical pins can be designed to have heads on them to keep them from falling out of the hole into which they are inserted, or they might have self-tensioning enhancements designed into the pins. They can also have two metal ends extending beyond the hole they are inserted into, allowing for the ends to be bent out or flared out wider than the hole opening providing a tension mechanism ensuring the pin does not inadvertently fall out. Sometimes is beneficial to use multiple together to ensure effectiveness.  Often a larger pin can be used for the sheer strength benefits and then smaller mechanical pin can be inserted orthogonally to the larger pin, at its end, to prevent the larger pin from falling back out of its hole.