A fastener, abbreviated as FSTNR, is hardware that mechanically joins two or more objects together.
Nomenclature & Symbols for
Nomenclature & Symbols
- Permanent - These parts will never be disassembled like rivets and welding.
- Removable - These parts can be disconnected without damaging the fastener like nut and bolt.
- Semi-permanent - These parts can be disconnected, but some damage can occurs to the fastener like a cotter pin.
- ASME B1.20.1 - Pipe Threads, General Purpose, Inch
- ASME B1.20.3 - Dryseal Pipe Threads, Inch
- ASME B18.12 - Glossary of Terms for Mechanical Fasteners
- ASME B18.18 - Quality Assurance for Fasteners
- A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
- Alloy steel - A steel that one or more elements (other than carbon) have been added.
- Annealing - A process of heat treatment that changes the properties of metals.
- Bolt - A fastener with a head and threaded on one end only.
- Bolt head - Formed by heating the end of a round piece of steel round bar then forged in to a head shape.
- BSF - British Sandard Fine
- BSW - British Standard Whitworth
- Cold forming - A material is placed between two dies and compressed into a shape.
- Corrosion resistant - The ability to resist corrosin under certain conditions.
- Cut thread - A threading method produced by removing material from the surface with a form cutting tool.
- Deformation - Is measured by how much an object is deformed from its origional dimensions.
- Effective diameter - See pitch diameter.
- Elastic modulus - The ratio of the stress applied to a body or substance to the resulting strain within the elastic limits.
- External thread - A screw thread that is formed on the external cylinder. Also called male thread.
- Fastener length - Measured from the top of the head to the bottom of the threads.
- Forging - The process of forming raw steel by displacement under force into specified shapes.
- Friction - The mechanical resistance to the relative movement of two surfaces.
- Friction coefficient - The ratio between two contacting surfaces and the frictional force that resists the normal force of the object.
- Hex head bolt - A bolt with six sided head.
- Hex head cap screw - A hex head screw with a flat and washer faced bearing surface under the head.
- IFI - Industrial Fasteners Institute
- Internal thread - A screw thread that is formed inside a hole. Also called female thread.
- Left hand thread - A screw head that rotates counterclockwise.
- Lock nut - Resists loosening under vibration and torque.
- Major diameter - The largest diameter of a screw thread.
- Minor diameter - The smaller diameter of a screw thread.
- Nominal diameter - The external size diameter designated of pipe or threads.
- Pitch diameter - See thread pitch diameter.
- Quenching - A process of quickly cooling an elevated temperature.
- Right hand thread - A screw head that rotates clockwise.
- Shank diameter - The smooth part of the bolt above the threads.
- Shear stress - Tends to deform the material by breaking rather than stretching without changing the volume by restraining the object.
- Static friction coefficient - The amount of force that resists motion that is on the verge of motion.
- Strain - The deformation, stretched or compressed, of a material compared to its original length.
- Stress - The force per unit area of cross-section.
- Tap bolt - A bolt that is threaded to the botom of the head.
- Tension strength - The capacity of a material to resist a force tending to stretch it.
- Thread angle - The angle between the thread flanks.
- Thread axis - The imaginary distance equally between the major and minor diameters.
- Thread count - The number of threads per inch (TPI), used for US threads.
- Thread crest - The peak of a thread at the major diameter.
- Thread flank - The side of a thread between the major and minor diameters.
- Thread height - The perpendicular distance between the major and minor diameters.
- Thread length - Length of the cylinder that is threaded.
- Thread pitch - The distance between threads measured in millimeters, used for metric threads.
- Thread pitch diameter - The imaginary diameter equal distance between the major and minor diameters. Also called effective diameter.
- Thread root - The bottom of the thread.
- Torque - A rotational moment.
- UNC - United National Course
- UNEF - United National Extra Fine
- UNF - United National Fine
- UNR - United National (UN)
- Yield point - The point where an elastic material is permanent change in length with no extra load force.