When components are standardised they are easier to work with because such components are interchangeable. For this to be possible the fundamental characteristics of standard parts must be defined by a central body and used by manufacturers and retailers.
Product designers should take advantage of the standards available for various types of fasteners.
Almost every possible fastener component has been standardised by international certification agencies and are used by fastener producers. It is very useful to refer them at the design stage itself. Avoiding non-standard fastener in the design helps reduce development and production cost.
Standards define at least one of the following features:
Head shape (e.g. hexagon head, hexagonal socket, raised countersunk head)
Type of thread (e.g. standard metric ISO thread M, sheet metal thread)
Material and strength class
Possible coatings or strength characteristics
Applicable standards for fasteners.
You can download many of the specifications from the link below.