ASME B18.12 pdf free download

ASME B18.12-2020 pdf free download.Glossary of Terms for Mechanical Fasteners.
ASME B18.12 is a summary of mechanical fastener terminology, related characteristics, and manufacture.
(a) 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 ofa mechanism or structure. Fasteners are used in just about every mechanical assembly, and they have been designed to meet the needs of products ranging from wristwatches to the space shuttle. Each fastener is produced with the degree of built-in precision and engineering capability needed to ensure adequate, sound service under preestablished environmental conditions.
(b) Bolts, Studs, Screws, Nuts, Washers, Rivets, Pins, and Custom-Formed Parts These are the general product families used to classify mechanical fasteners. Within each product family are numerous fasteners whose names either conform to the technical language of a national standard or relate to their original applications, e.g.,”stove holt or “carriage bolt.” The names given to fasteners appear to be as limitless as the imaginations of their designers. While many fasteners may look alike, each has defined engineered capabilities based upon its intended application.
(c) Primary Operations. Mechanical fasteners are produced by forming or screw machine operations.
(1) Forming may produce thousands of fasteners per minute with looser tolerance (depending on the size and configuration of the fastener) and typically creates minimal scrap.
(2) Screw machining is significantly slower and typically produces tighter tolerance but has a higher risk ofcreating scrap.
(d) Secondary Operations. Fasteners typically undergo several secondary operations or processes, such as thread rolling, heat treating, or plating.
1.2 Referenced Documents
The developers of this Standard wrote a number of terms based on the language found in more than 230 standards and other publications of the following organizations:
(a) The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016.5990 (www.asme.org)
(b) American Society for Testing and Materials (ASTM International). 100 Barr Harbor Drive. P.O. Box C700. West Conshohocken, PA 19428.2959 (www.astm.org)
(c) Industrial Fasteners Institute (IFI), 6363 Oak Tree Boulevard, Independence, OH 44131 (www.indfast.org)
(d) Research Council on Structural Connections (RCSC), do AISC, One East Wacker Drive, Suite 700, Chicago. IL 60601 (www.boltcouncil.org)
(e) Society of Automotive Engineers (SAE International), 400 Commonwealth Drive, Warrendale, PA 15096 (www.sae.org)
2 TERMINOLOGY
2.1 BasIc Fastener Terminotoqy
2.1.1 CommerciaL Fastener
commercial fastener: a fastener manufactured to published consensus standards and stocked by manufacturers and
distributors.
2.1.2 Compression Fastener
compression fastener: a fastener whose primary function is to resist compressive forces.
2.1.3 Endurance Limit or Endurance Strength
endurance limit or endurance strength: the maximum alternating stress that a fastener can withstand for a specified number of stress cycles without failure.
2.1.4 Headed Fastener
headed fastener: a fastener that is enlarged or formed at one end.
2.1.5 HeadLess Fastener
headless fastener: a fastener, either threaded or unthreaded, that is not enlarged at either end.
2.1.6 High-Strength Fastener
high-st rength fastener: a fastener whose high tensile and shear strengths are attained through a combination of materials, work-hardening, and heat treatment. These fasteners usually have a tensile strength in excess of 120,000 psI.
2.1.7 Lock Pin and Collar
lock pin and collar: a headed and externally grooved mechanical device designed for insertion through holes in assembled parts. A cylindrical collar is swaged into the external groove as the lock pin is hydraulically tensioned. Collars either are smooth bored or contain a fit-tab. An optional flange provides a built-in washer.
2.1.8 Mechanical Properties
mechanicaiproperties: the properties of a fastener in reaction to applied loads. The mechanical properties of the fastener are rarely those of the raw material from which it was made. Properties such as tensile and yield strengths, hardness, and ductility will vary widely depending on the choice of manufacturing methods and metallurgical treatments.
2.19 Modified Standard
modifiedstandord: a standard part that has one or more of its features or characteristics slightly changed. Such a part is typically customized to a customer’s specs for a particular application, but the change is such that any interested manufacturer can produce the modified part.
2.1.10 Nonstandard Fastener or SpeciaL Fastener
nonstandard fastener or special fastener: a fastener that differs in size, length, configuration, material, or finish from established and published standards.
2.1.11 Physical Properties
physical properties: inherent properties in the raw material that remain unchanged or undergo only slight alteration in the fastener following manufacture.These properties may include density, thermal conductivity, and magnetic susceptibility.
2.1.12 Part ldentlIylng Number (PIN)
Part Identifying Number (PIN): a 21-character code that Identifies an ASME BiB-manulactured product by specific characteristic fields, such as fastener family identification, ASME B18 standard identification, fastener style or type, thread series, nominal diameter, nominal length or dimensional/other characteristics, material and treatment, plating, coating, passivation. and special features relevant to the fastener product.
2.1.13 Precision Fastener
precision fastener: a fastener manufactured to close dimensional and geometric tolerances.
2.1.14 Proof Load
proof load: the tensile load that a fastener must support without evidence of permanent deformation. Proof load is an absolute value, not a maximum or minimum value. For most carbon or alloy steel fastener strength grades or property classes, proof loads are established at approximately 90% to 93% of the expected minimum yield strength. Proof loads are frequently used as design values in joint analysis and fastener selection.
2.1.15 Proof Test
proof test: a form of tensile test in which the maximum load applied is the proof load value in the applicable specification.ASME B18.12 pdf download.