Their use is voluntary. Standards become mandatory when they have been incorporated into a business contract or incorporated into regulations. A code is a standard that has been adopted by one or more governmental bodies and has the force of law. S tandards are a vehicle of communication for producers and users. They serve as a common language, defining quality and establishing safety criteria.
Interchangeability is another reason.
It is not uncommon for a consumer to buy a nut in California for a bolt purchased in New Jersey. Within ASME, the Council on Codes and Standards is one of five councils that report to the Board of Governors. Under this Council, there are six standards developing supervisory boards that manage over 100 consensus committees with 3700 volunteer members and four advisory boards. The supervisory boards in turn have standards committees, each responsible for an area of standards development. The advisory boards deal with metrication, international standards, hearings and appeals and council operations.