Fastener Standards

Fastener Standards address the dimensions, testing, and use of screws, bolts, nuts, rivets, flanges, studs, and so forth. With ubiquitous usage in many fields of industry, fasteners come in a similarly wide variety, differing even within the range of a single design in everything from size to material, coating, inspection criteria, etc. Thus, standardization serves its role to assist interchangeability between different parts and manufacturers, as well as the reliability of those parts.

Standards developing organization such as the Industrial Fasteners Institute (IFI), SAE International (SAE), the International Organization for Standardization (ISO), and others have produced the below voluntary consensus standards.

General Fastener Standards

General fastener standards include dictionaries of terminology, abbreviations, and designations applicable to multiple types of fasteners, across multiple applications and industries, serving as a foundation for more nuanced standards that are then free to delve into the specifics of a specific type of fastener to be used in a specific application. Additionally, standards have been developed for quality assurance to promote both thoroughness and fairness in assessments.

Fastener Standards for Screws, Bolts, and Studs

Screws, bolts, and studs share many features with regard to their form, and, as a result, many standards apply to more than one kind of these closely related fasteners. However, there are of course differentiating features between them, and so they also have standards specific to each of them in addition to unifying standards such as those for threading, heads, and sockets.

Fastener Standards for Nuts

Fastener standards for nuts cover multiple kinds of self-locking nuts, as well as a similar range of hex nuts. Additionally, standards have been developed to address test methods, surface discontinuities, mechanical and material properties, and the properties of nuts to be used in specific applications. Both inch and metric nuts are covered.

Fastener Standards for Rivets

Fastener standards for rivets cover multiple kinds of blind rivets, addressing closed, open, and self-plugging varieties. Other rivet standards address the mechanical and material properties of the alloys the rivets are made from. Given the high performance requirements for rivets in the aerospace industry, there are separate standards addressing aerospace rivets, as well as additional ones for other specific applications.

Fastener Material Standards

Fastener standards for materials address the very metals that fasteners are composed of. With different applications requiring varying levels of corrosion resistance, resistance to deformity and high strength at different high temperatures, different manufacturing processes, dimensions, as well as considerations of matching metals to prevent galvanic corrosion.

Fastener Assembly Tool Standards

Fastener assembly tool standards cover the tools, and their variable parts, that handle the fasteners during their installation. Given the variability within screwdrivers, starting from whether they are machine or hand operated, and continuing down all the way to the bits that actually make contact with the fastener, standardization promotes interchangeability between tools and parts of different manufacturers, and fasteners of yet a different manufacturer.

Fastener Wrench Standards

Fastener standards for wrenches have to encompass the wide range of fasteners that wrenches are used upon, addressing wrenches intended for both metric and inch fasteners, and the necessary dimensions of the parts of the wrench for them to be able to properly apply torque to fasteners while hand-held versions remain ergonomic and machine driven remain compatible.

Standards for Fastener Test Methods

Test method standards for fasteners cover test procedures for screws and nuts, gauging their performance under the conditions they are intended for. Test procedures are available for both inch and metric series fasteners.

Standards for Fastener Surface Discontinuities

Standards for surface discontinuities on fasteners establish limits and acceptance criteria for surface discontinuities on bolts, screws, studs, and nuts. Particular attention is paid to screw threading on high-strength fasteners intended for use under high pressures. Standards are available for both inch and metric series fasteners.

Wood Fastener Standards

Standards for wood fasteners address considerations applicable specifically to fasteners used with wood, as opposed to the more commonly used metal. Wood materials covered are solid timber, glued laminated timber, wood-based sheet products, and bamboo.

Coating Standards for Fasteners

Standards for fastener coatings deal with protective coatings, the design of fasteners that have coatings applied to them, and the requirements for the application of the coating itself. Since matching the coating material and procedure to the fastener material and the intended application is balancing many variables, standardization promotes reliability in design across manufacturers.

Fastener Standards for Washers

Standards for washers cover suitable washers for a variety of different fastener types, as well as addressing specifications for washers of differing strengths for more demanding applications in industries such as aerospace. Standards for washers are available for both inch and metric series fasteners.

Torque Standards for Fasteners

Standards for the torque-tension relationship in fasteners cover tests for determining it on both externally and internally threaded fasteners, tightening procedures, and quality control methods for those procedures, as well as laying out the interactions between all the applicable variables at play between different physical forces. Torque-tension relationship standards are available for both inch and metric series fasteners.

Standards for Medical Fasteners

Standards for medical fasteners address the nuances specific to medical usage of fasteners, such as the potentially catastrophic interactions between the human body and surgical implants. Medical fastener standards cover their mechanical requirements, dimensions, test methods, and the design of plates for screws to interact with.

Corrosion Standards for Fasteners

Standards for corrosion dealing with fasteners address the ever-present consideration of corrosion that comes with using (multiple) metal materials. Providing methods of corrosion prevention and methods for accelerated corrosion tests, these developed standards serve to promote reliable durability in the manufacture and use of fasteners.