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Description / Abstract:
This Standard is a summary of nomenclature and terminology
currently used to define and/or describe mechanical fasteners,
related characteristics, and the manufacturing processes that
produce these products. Utilization of these terms by manufacturers
and consumers is intended to reduce or eliminate confusion and
serve as a sound basis for communication.
(a) Primary Operations. Mechanical fasteners are produced by
forming or screw machine operations. Forming is generally scrapless
and, depending upon size, may produce fasteners at rates exceeding
500 pieces per minute. Screw machining, although more tightly
toleranced, is significantly slower and generates scrap because it
involves the removal of material.
(b) Secondary Operations. Fasteners generally undergo
several secondary operations or processes, such as thread rolling,
heat treating, or plating.
(c) Fastener. A fastener is a mechanical device
designed specifically to hold, join, couple, assemble, or maintain
equilibrium of single or multiple components. The resulting
assembly may function dynamically or statically as a primary or
secondary component of a mechanism or structure. Based on the
intended application, a fastener is produced with varying degrees
of built-in precision and engineering capability, ensuring
adequate, sound service under planned, pre-established
environmental conditions.
(d) Bolts, Studs, Screws, Nuts, Washers, Rivets, Pins, and
Custom-Formed Parts. These items are the general product
families in which mechanical fasteners are best classified. Within
each product family are numerous types that may have a name
conforming to the technical language of a national standard or
alternately may have a name that has its origins in commercial or
marketing nomenclature often taken from its intended application.
Such names, for example, include the "stove bolt" and "carriage
bolt." Because mechanical fasteners are used in just about every
mechanical assembly, they necessarily have been designed to meet a
broad range of applications from watch and computer assembly to the
space shuttle design. The names given to fasteners appear to be as
limitless as the designer's imagination. While many fasteners may
look alike, they generally have defined engineered capabilities
based upon their intended application.