In general the industrial fasteners come in three standard sizes. These are termed as ASTM, ISO and SAE. These are the name of three organizations that are responsible for the standardization of the industrial fasteners. In fact these three organizations namely

The American Society for Testing and Materials,
The Society of Automotive Engineers, and
International Organization for standards,
Decide the standards and specifications for all types of fasteners. Though their methods of testing and measuring differ vastly from each other, the end objective is identical, to see that the quality of the products are not taken below a specific standard by the unscrupulous traders.

There can be no two opinions that fasteners are one of the major forces that are holding the industrial world in a compact manner. Fasteners are responsible for joining together and keeping in tact various parts of machines. All types of anchors, bars, screws and bolts are termed as fasteners. A fastener is always unique in the sense that it joins two objects and makes them one.

Fasteners could be made of multifarious materials. Though most of the fasteners are made using metals, plastic is also used in several cases. This changed used is mostly in case of those articles where removal of screw is denied or where other alternatives are not readily available. Screws are the most well known fasteners, followed by the sockets. Though the shape and size of fasteners widely vary, the aim is to bind two objects together.