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Last Updated: Apr 22, 2014 URL: Print Guide RSS UpdatesEmail Alerts

Standards: What, How & Why Print Page

What are standards? specifications? codes?

A standard can be defined as a test method, definition, or recommended practice regarding manufacturing, testing, dimensions, and/or certification of raw materials and finished goods.   The intent in creating a standard is to produce goods that are safe and reliable.  Standards are usually created by organizations that are purposed for that activity.  The terms standard, specification, and code are often used interchangeably. Voluntary or mandatory compliance is the distinguishing feature. Standards and codes are subject to mandatory compliance when such standards and codes are referenced to in regulations such as the Code of Federal Regulations or in municipal building codes.  Legal liability is a result of such referencing.   The same codes and standards are enforceable via inspection. Construction, manufacturing, food service and other operators are subject to fines when they fail said inspections. When a legal suit is brought forth, the outcome hinges on the extent of compliance to the respective standard, code, or specification. The intent of this regulation is safer products, processes and work environments. 

The word “code" is a term of much broader meaning than either specification or standard and can best be described as a set of rules established by a recognized authority examples such as the US federal government's Code of Federal Regulations (CFR), and the American Society of Mechanical Engineers' (ASME), Boiler and Pressure Vessel Code.  In adopting the rules that make up the various codes, consideration is generally based on health, safety, and environmental protection. The code-formulating bodies, in addition to writing their rules, usually adopt standards and specifications either in whole or in part to become a part of the code.[1] Industries must follow the codes that are adopted by the respective jurisdiction.   For example, a city (a type of jurisdiction) may decide to adopt the National Electical Code which then establishes the rules by which electrical contractors must adhere.  Inspection of construction work is driven by the NEC for those jurisdictions. 

Specification.  Avoid splitting hairs with over these definitions.  A specification is a form of standard, which precisely states a set of requirements to be satisfied.  These requirements might be chemical composition, mechanical properties, or any other requirement that is necessary to develop the quality and reliability of an end product. [1].   Specifications are also referred to as "specs".  Specifications are often thought of functionally, as follows.  Specifications capture the essence, or "gist", ie the minimal thresholds of the standard or code in which they lie.   Wherever you see in the text (of a standard or code) a list of instructions, the same list of which indicates the order of progression of a series of steps that must be followed with precision, you are looking at the "spec".  There may be more than one spec within the standard or code, depending on the complexity of the topic.

[1] Adapted from the Steel Founders of America




[1] The structure and content of this guide is based on the guide, Standards & Specifications: A How-To Guide, authored by Lorriw Pellack at Iowa State University.


Why? How? Historical

Why? Standards are important for safety, reliability, quality, ease of use, interchangeable parts; and consistency of products and processes across international borders. Standards are written for, but not limited to raw materials; manufactured products; methods of analysis, such as chemical, electrical, or mechanical; nondestructive testing; units of measure, such as time, distance, or mass; information privacy issues; environmental considerations; manufacturing processes; etc. Internationally accepted standards facilitate international trade.

How are standards created?  Standards Development Organizations (SDO's) are composed of individuals from public and private industry, government and non-governmental organizations.  Standards organizations meet on a regular basis to update existing standards and write new ones in response to new technologies, changes in laws, regulations, safety issues, performance criteria, etc.   The typical standard is updated every 5 years.  

What sparked the creation of standards in the first place?  As societies entered the industrial age, the use of materials increased exponentially. Assessment of material quality by the craftsman became increasingly difficult in particular in the manufacture of steel.  The discipline of engineering provided a scientific means of testing material quality; craftsmen who were not yet accustomed to the new materials and the skills needed to verify quality soon adapted the tools and methods required to make those assessments.  The manufacture of steel became subject to disagreement between the steel mills and the railroads, when it was discovered that steel failed under stress due to insufficient material quality and heat treatment.   The American Society of Testing & Materials formed from the participants who created the standards for manufactured steel.   Any manufacturer who could comply with the new standards could participate in the market and thus steel manufacturing that satisfied the needs of the railroad and other industries grew as a result.  Nearly every type of material and manufactured good from asphalt to zippers is governed by any number of relevant standards.  


Metallurgical Failure Analysis

The objective of this paper is to introduce the reader to the procedures generally followed when conducting a metallurgical failure analysis. Six failure case reports are provided to help you to learn by example.

'To increase the odds of completing a conclusive failure analysis while at the same time saving time and money, investigations should be carried out using a systemic approach similar to that outlined in Figure P.1. It is important to note however, that it is often impossible to foresee results that might require the investigator to go back and repeat a test. A simple way reduce the occurrence of this is to go into a case well informed on how similar systems have failed. An excellent source of for this type of information is the ASM handbooks, particularly volume 10 on "Failure analysis and prevention" '


Exploding Boilers, You Say!!!

Because it’s a catastrophe when a screw doesn’t fit.

The most serious problem facing 19th century engineers was exploding boil-
ers. Heating water to produce steam and converting that steam into energy to
power machinery revolutionized the production of goods. To build up pressure,
steam must be contained in some type of vessel; but uncontrolled, pressur-
ized steam can burst a vessel even if it’s made of steel. For want of reliably
tested materials, secure fittings, and proper valves, boilers of every descrip-
tion, on land and at sea, were exploding with terrifying regularity. (They would
continue to do so into the 20th century.) Although engineers could take pride
in America’s strides in technology, they could not ignore the 50,000 dead and
2 million injured annually by such accidents. Thus, mechanical engineers in
the 1880s began seeking reliable methods for testing steam boilers.


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