Fasteners are machine made tool elements that are used to hold other units together by mechanical force. There are various types of fasteners used in the industrial world and domestic world such as nails, screws, nuts, hinges, bolts, studs, and rivets, etc. Fasteners are made of a variety of materials such as heat treated steel, plastics, copper and brass. Some examples of fastener use are inside automobiles, domestic appliances, white goods and machine tools. Special fasteners are used in orthopedics to hold together broken bones and industrial fasteners are used for heavy duty industrial applications.
Screws have either metric or imperial threads of different pitches and outside diameters in them. The thread fit mates with either nuts or internal threads in the mating part. Threads can be either ground, cold rolled or turned. Rivets have ground or turned ODs. The rivet body, with a head on one end, is inserted in the holes of two mating parts and another head is formed at the other side by hammering the exposed end.
Nuts and bolts are two more examples of threaded fasteners which are vital in industry, and essential for the mechanic. Bolts are available in different types and materials, dependent on the job they're doing. The phrase wing nut is often heard and wing nuts are often used on boats, where it is important to be able to hand tighten the fastener. A lag bolt looks similar to a regular bolt but it has a pointed rather than a blunt tip. Lag bolts are mainly used in construction environments. Silicon bronze lag bolts are ideal for wooden boat construction and repair. Carriage bolts are often used in wood working and they have a domed top and a square under the head.
Fasteners are usually not made very hard, but are suitably toughened. This is to ensure that they are slightly flexible and do not break off easily. It is also to make sure that the body or head of the fastener can be easily cut off with a hacksaw. Of course you usually need some type of hand tool such as a wrench, hammer or screwdriver to properly use a fastener
Fasteners are also pretty much useless to you if you use the wrong type. You must make sure that you use the right type of fastener for the task you are doing. If you are hanging something up on drywall you will need drywall screws and mounting hardware. Plumbing and electrical work also require specialized fasteners, which are often in the form of couplings. Nails must be selected for the job and material that they will be used on and when you need to replace a screw you need to make sure you find the right size.