McGuire Glossary of Fastener Terminology

A - 139 terms

A SHEET METAL SCREWS - Sheet metal screws (AKA Tapping Screws) with (a) sharp-pointed ends: and (b) fewer threads per inch than type AB screws; and (c) deeper threads with better gripping power than type AB. The IFI incorrectly labels the type A an obsolete thread thought it is universally preferred in 18-8 stainless steel over type AB, especially by the marine industry.

A2 - The most commonly produced grade of stainless steel, grade 304 and is the notification as a metric fastener. It contains 18% Chromium and 8% nickel, thus commonly called 18-8 Stainless Steel. A2 is an austenitic steel and is non-magnetic. The chromium provides a corrosion and oxidation resistance, however, it can tarnish. Stainless steel A2 property classes for fasteners are 50, soft or 70 cold-worked.

A286 - This is an iron-based superalloy which features an austenitic structure with high amounts of nickel and chromium. A286 (or Incoloy) is ideal for high strength and corrosion resistance up to 704 degrees C and for lower stress applications at high temperatures. Low temperature capabilities including ductility, non-magnetic, high strength at -196 degrees C

A2LA - A2LA are the initials of American Association for Laboratory Accreditation, a non-profit accrediting agency specializing in the accreditation of calibration and testing laboratories.

A325 - Heavy Hex Head Structural Bolts

A4 - Stainless steel grade 316 and a notification for metric fasteners. Commonly used in marine applications where you need more corrosion resistance. Adding molybdenum (2-3%) to the mix provides this extra resistance. A4 grade is austenitic, non-magnetic , the molybdenum increases the corrosion resistance to withstand attack from many industrial chemicals and solvents and chlorides. A4 grade stainless steels come in property classes : 50, soft and 80 high-strength.

A490 - Heavy Hex Structural Bolts

A574 - Strength Grade for socket head cap screws

AAR - Association of American Railroads

AASHTO - American Association of State Highway and Transportation Officials

AB MODE - An abbreviation for Alternate Blow Mode. A machine feature that allows for the feeding of the wire on every other machine stroke. This allows for the forming of some higher load parts on a given machine size.

AB SHEET METAL SCREWS - Sheet metal screws with pointed ends similar to type-A and dimensions similar to type B sheet metal screws. Type AB has more threads per inch than the Type A Sheet Metal Screw.

ABRASIVE - NATURAL - (Sandstone, emery, corundum, diamonds) or artificial (silicon carbide, aluminum oxide) material used for making grinding wheels, sandpaper, abrasive cloth and lapping compounds.

ABS - Plastic material, a class of plastic based on acrylonitrile-butadiene-styrene copolymers.

ABS (PLASTIC) - Excellent impact strength and impact resistance. Used extensively in appliances, automotive and computer components. May be painted and plasted.

AC - Active Coils

ACCEPTABLE QUALITY LEVEL (AQL) - The acceptable quality level is a nominal value expressed in terms of percent defective, i.e. defects per hundred units by which a group of sampling plans is identified. The AQL is specified for each individual characteristic and is not cumulative.

ACCEPTANCE NUMBER (Ac) - The acceptance number is the maximum number of defects for a specific characteristic in any given sample resulting in the acceptance of the lot.

ACCREDITATION - Is a process used by a qualified independent agency to verify the quality system and technical capability of a calibration laboratory to a recognized standard such as ISO 17025.

ACCURACY - Defines how close to a measured value is to the true value of the dimension.

ACCURATE - Conforms to a standard or tolerance

ACETAL (DELRIN(R), CELCON(R) (PLASTICS) - Acetals display good impact resistance, dimensional stability and outstanding surface hardness due to their high degree of crystalinty. They have high dielectric strength and are resistance to many solvents. They also exhibit negligible water absorption. Typical applications include roller bearings, gears, reels, counters, control cams, valves and pump parts.

ACI - American Concrete Institute

ACME THREAD - A thread form which has a 29 degree thread angle with a thread height half of the pitch, the apex (or crest) and valley (root) are flat. Used in applications for feed or adjusting screws on machine tools.

ACORN DIE - A form of threading die for use in screw machines. The cutting portion resembles an acorn.

ACQ - Pressure treated lumber is treated with Alkaline Copper Quaternary (ACQ) an environmentally friendly water-based preservative that is free of arsenic and chromium.

ACR - Anti Cam-out Ribs on the Phillips II drive recess to improve drive bits from cam-out during the installation phase. There are ribs on the drive bit that engage the fastener recess to reduce stripping, provide increased torque, enhance off-angle drivability, and offer a stick fit that makes screw driving easier.

ACR PHILLIPS II PLUS - ACR Phillips II Plus is a screw-drive design that can be driven by a #2 Phillips driver or a #2 Robertson driver, but when driven by a Phillips II Plus bit, the combination results in a stick-fit interface.

ACTIVE COILS - (Also known as effective coils of working coils) - The number of coils which are free to move when the spring is loaded.

ACTIVE COILS (SPRING TERM) - Coils which are free to deflect under load.

ACUTE ANGLE - An angle that is less than 90 degrees.

ADAPTER - A tool holding device for fitting together various types or sizes of cutting tools to make them interchangeable on different machines.

ADDITIONAL AGENT - A material added in small quantities to a solution to modify its characteristics or the properties of the deposit obtained from the solution.

ADHESION - The strength of the bond between a coating and its substrate which is measured as the force per unit area required to separate them

ADHESIVE ANCHOR - Typically, a threaded rod or rebar that is installed in a predrilled hole in a base material with a two-part chemical compound.

ADHESIVE BONDING - The joining of two or more materials through the use of adhesives such as liquids, drops or gels.

ADVANCED TRIM HEAD - The AXIS wood screw Trim Head is slightly larger in diameter than industry standards. This combined with the patent pending Turbine Ribs gives maximum holding power while leaving a clean, professional finish.

ADVANCING KICKOUT - A machine mechanism (normally found on Single Die Double Stroke Rivet Headers) where the die kickout pin moves forward between the cone and finish blows to expose material to be upset into the head

AESTHETIC DESIGN HEAD - Head is shaped to fit a neat design in cabinetry on ETX wood screws

AGE HARDENING - A process of aging that increase hardness and strength and ordinarily decreases ductility. Age hardening usually follows rapid cooling or cold working.

AGING - A spontaneous change in the properties of a metal usually associated with the recovery of metal from an unstable condition produced by quenching or by cold working (strain aging). Age hardening and Aging are terms commonly used synonymously. See Precipitation Hardening.

AIR HARDENING - (Air Quenching) A hardening process wherein the steel is heated to the hardening temperature and cooled in air. Unless steel is high in carbon or alloy, it will not show much increase in hardness when air hardened. Mainly used with tool steels and stainless steel. Modern air-hardening steels are characterized by low distortion during heat treatment because of their high-chromium content. Their machineability is good and they have a balance of wear resistance and toughness.

AIR-LIFT HAMER - A type of gravity drop hammer that uses an air cylinder to raise the ram and deliver blows to a forging. Because the velocity can be controlled, each blow can vary based on the amount of force needed to properly forge a metal.

AIR-LIFT HAMMER - A type of gravity-drop hammer in which the ram is raised for each stroke by an air-cylinder. Because of the length of stroke can be controlled, ram velocity and therefore the energy delivered to the workpiece can be varied. Also see Drop Hammer and Gravity Hammer.

AIRCRAFT FASTENER SPECIFICATIONS - Each classification refers to the governing body that has approved, and maintains the drawn, published specifications for each part.

AIRCRAFT QUALITY - Stock and forgings used for aircraft applications including Aerospace that require close monitoring during production. This helps reduce flaws both on the surface and internally as well as cracks, inclusions, and segregations of the forging.

AIRCRAFT QUALITY FASTENERS - To be used in highly stressed applications, are to be produced under closely controlled, special and in most cases restricted methods of manufacture and inspection.

AISC - American Institute of Steel Construction. A technical institute and trade association established to serve the structural steel design community and construction industry in the United States.

AISI - The American Iron and Steel Institute. An association of North American steel producers developed in response to the need for a cooperative agency in the iron and steel industry for collecting and disseminating statistics and information, doing investigations, providing a forum for a discussion of problems and generally advancing the interest of the industry.

ALIGNMENT PLUG - A tooling component used to represent a formed part during the setup of the transfer fingers in the external setup fixture. These plugs change to suit the part diameter being gripped.

ALKALINE - The ionic substance that has a pH value greater than 7. A base that dissolves in water and acts as an electrolyte in the presence of metal.

ALKALINE BLACKENING (BLACK FINISHING) - Producing a black oxide coating on steel by immersion in hot alkaline salt solutions.

ALKALINE CLEANING - Cleaning by means of alkaline solutions.

ALL-METAL - Often refers to locknuts which have no nylon inserts. These nuts are effective under harsh temperatures and extreme corrosive conditions.

ALLEN WRENCH - Commonly referred to as a hex key or an Allen key. This tool is used to drive internal hex socket screws and other hexagonally shaped socket fasteners.

ALLOW FOR SET (SPRING TERM) -

ALLOW FOR SET (SPRING TERM) - When a spring is supplied longer than specified to compensate for length loss when fully compressed in assembly by customer, recommended for large quantity orders to reduce cost.

ALLOWABLE LOAD - The maximum design load that can be applied to an anchor. Allowable loads for mechanical and adhesive anchor are based on applying a factor of safety to the average ultimate load.

ALLOWABLE LOAD - The maximum permissible load in a structural part or assembly. As applicable, it can be specified strength of the hardware (e.g., in a fastener specification): a statistically based, lower-bound, load carrying capacity derived from the test data; or the load derived from the allowable stress of the materials.

ALLOWABLE STRESS DESIGN (ASD) - A design method in which an anchor is selected such that service loads do not exceed the anchor's allowable load. The allowable load is the average ultimate load divided by a factor of safety.

ALLOWANCE - A specific amount of clearance or interference between threads. Also an intentional difference between the maximum material limits of mating parts. It is a minimum clearance (positive allowance) or maximum interference (negative allowance) between such parts.

ALLOWANCE - The prescribed difference in dimensions of mating parts to provide a certain class of fit

ALLOWANCE - The prescribed diference between the desgin thread form and basic size. Allowances can be used either to accommodate thread coatings or faciliate assembly

ALLOY - A material with metallic properties composed of two or more elements at least one of which is a metal. A steel that contains a small amount of various alloying elements including silicon, molybdenum, manganese, vanadium, nickel, titanium, copper, chromium, and aluminum. Alloys change the performance of the steel in strength, corrosion resistance and other properties demanded by the application.

ALLOY - A metal formed by a mixture of two or more different metals

ALLOY 20 - This alloy has approximately 20% Chromium and 34% Nickel plus 3% to 4% Molybdenum. It is very corrosion resistant and is especially popular when in contact with sulfuric acid.

ALLOY 600/625 - High Temperature Alloy

ALLOY 718/722/ X-750 AM350 - High Temperature Alloy

ALLOY DEPOSITION - Co-deposition of two or more metals.

ALLOY STEEL - A steel containing elements, other than carbon, which have been added to obtain definite mechanical or physical properties, such as higher strength at elevated temperatures, toughness, etc.

ALLOY STEEL - Steel which contains in addition to the normal elements of iron, carbon, and manganese, one or more elements in sufficient quantity to impart improved mechanical properties. The small amounts of elements and impurities such as sulfur, silicon, phosphorus, and aluminum which are usually present in any steel are not considered alloys. If manganese is added to steel in sufficient quantity, it may be considered as an alloy in alloy steel.

ALLOY STEEL - A mixture (or alloy) of ordinary steel added to other metals besides carbon with the specific purpose of attaining certain characteristics such as higher strength. A few exceptions to this definition exist, however, so that a chromium content above 4% is not considered alloy steel and above 12% is considered stainless steel.

ALLOYING ELEMENTS - Chemical elements combined with a metal in order to alter and improve the properties of the base metal.

ALUMINUM - An element with the atomic number 13. This material is known for its excellent strength to weight ratio and is used widely in metal. Aluminum is blueish and silvery-white, very light, malleable, and ductile with high heat and electrical conductivity. It is non-magnetic and one-third the weight of steel with good corrosion resistance against certain chemicals and acids but weak resistance against other elements such as sea water.

AMPLIFER (GAGING) - The readout of an air or electronic gage system. It displays readings on a scale as dimensional values. When connected to air or electronic gage tooling, readings are amplified many times, allowing the user to easily red read the size being measured.

AMPLIFIER - The readout of an air or electronic gage system. It displays readings on a scale as dimensional values. When connected to air or electronic gage tooling, readings are amplified many times, allowing the user to easily read the size being measured.

AMS - Aeronautical Material Specifications are material and process specifications for aircraft components confirming to established engineering and metallurgical practices in the aircraft industries. They were developed by the SAE Aeronautics Committee.

AMSLER - Swiss manufacturer of fatigue testing machines. The Amsler Vibrophone, a high frequency electro magnetic resonance machine, is used extensively for fatigue testing by the fastener industry.

AN SPECIFICATIONS - Dimensional standard for aircraft fasteners developed by the aeronautical standards group. All drawings are prefixed by AN.

ANAEROBIC ADHESIVE - An adhesive which hardens in the absence of air, such adhesives are often used as a thread locking medium.

ANCHOR BOLTS - A steel rod or bar with one end intended to be embedded in concrete and the other end threaded and projected for anchoring material to concrete. The end cast in concrete may be straight, bent hook, a forged head or welded attachment to resist forces imposed on the anchor bolt.

ANCHOR CATEGORY - The classification for an anchor that is established by the performance of the anchor in reliablility tests such as sensitivity to reduced installation effort for mechanical anchors or sensitivity to hole cleaning for adhesive anchors.

ANCHOR SPACING - The distance from centerline to centerline between two anchors.

ANGLE CONTROLLED TIGHTENING - Method of tightening where the person installing the fastener removes the slack from the assembly, and then tightens the fastener a prescribed amount (e.g. 120 degrees) based on the length of the fastener. This method is often coupled with the use of torque for the initial "snug" tightening

ANGLE CONTROLLED TIGHTENING - A tightening procedure in which a fastener is first tightened by a pre-selected torque (called the snug torque) so that the clamped surfaces are pulled together, and then is further tightened by giving the nut an additional measured rotation. Frequently bolts are tightened beyond their yield point by this method in order to ensure that a precise preload is achieved. Bolts of short length can be elongated too much by this method and the bolt material must be sufficiently ductile to cater for the plastic deformation involved, Because of the bolt being tightened beyond yield, its re-use is limited.

ANGLE NUTRUNNER TOOL - Angle nutrunners are well suited for many assembly applications. The minimal dimensions of angle heads allow them to reach into restricted places. which longer effective length reduces the torque reaction forces on the handle. For higher torque applications, these tools can be fitted with torque reaction devices.

ANGLE OF GRIND - Angle subtended by the ground and surface of the spring.

ANGLE OF HEAD - In countersunk heads, the included angles of the conical under portion or bearing surface, usually 82 degrees or 100 degrees. Standard metric countersunk screws have a head angle of 90 degrees.

ANGULAR RELATIONSHIP OF ENDS (Spring Term) - The relative position of the hooks or loops of tension springs, or the legs of a torsion spring, to each other.

ANGULARITY - The angle between the axis of two surfaces of a fastener.

ANION - A negative charged ion.

ANNEAL - Subjecting to high heat, with subsequent slow cooling to remove effects of cold working, to soften material hardened in heat treatment, to increase ductility and relieve stress; heating metal to a temperature above the critical range, holding it at that temperature a sufficient length of time for it to be heated through its full volume, and slowly cooling it through the critical range: cooling may be performed by cooling the metal slowly in the furnace, or by allowing it to cool to room temperature.

ANNEALED - A fastener is considered in the annealed state when it has been heated and cooled to make it soft - that is, free from hardness (stresses) caused by working or previous heat treatment. Also refines it structure or changes it ductility, toughness, or other properties.

ANNEALING - A heat treating process in which an iron-based metal is fully austenized and allowed to cool slowly, thereby relieving stress and often decreasing strength properties while increasing the ductility.

ANNEALING - The controlled heating and cooling of a metal to remove stresses and to make it softer and easier to work with.

ANNULAR FETTER - Assymetrical thread form with sharp crest and root-annular are ground and helical are milled Straight faced (angle or duplex) or single faced Gimlet.

ANODE - The material in a corrosive attack that becomes corroded.

ANODE - (1) in electrolysis, the electrode at which negative ions are discharged, positive ions are formed, or other oxidizing reactions occur. (2) The object which is intended to perform these functions.

ANODE BAGGING - Some anodes (e.g. Nickel anodes) are put in a cloth bag, before suspension in solution, so that the insoluble particles from the anode are collected in the bag instead of falling into the solution.

ANODE CORROSION - Dissolution of anode metal by the electrochemical action in the plating cell.

ANODE EFFICIENCY - Current efficiency of a specified anodic process.

ANODE FILM - (1) The thin layer of a solution which is in contact with the anode and differs in composition from the bulk of the solution. (2) Solid film formed on the anode during operation.

ANODIC (REVERSE) CLEANING - Electrolytic cleaning in which the work piece is the anode.

ANODIC COATING - (1) A metallic coating on a metal surface, the metal of the coating being less noble compared to that of the base meatal. (Sacrificial coating). (2) A protective, decorative, or functional coating, formed by conversion of the surface of a metal in an electrolytic oxidation process (See Anodizing)>

ANODIZING - The formation of an oxide film on the surface by means of an anodic treatment. This is commonly used on aluminum. Acid electrolytic treatment with frosty-etched appearance. Hard oxide surface gives excellent protection and reduced porosity. Tempered alloys can be dyed any color Type 1, Class 2. Good paint base and good for close tolerance parts.

ANODIZING (ANAODIC OXIDATION) - An electrolytic oxidation process in which the surface layer of a metal is converted to a coating having protective, decorative, or functional properties.

ANOVA - An abbreviation of analysis of variance.

ANSI - American National Standards Institute establishes the "Unified Screw Thread Standards" which regulates the fastener thread industry.

ANSI/ASME NOMENCLAURE (B1.1 & ALL) - The various "B" numbers are standards set by ASME regarding various aspects of fasteners. The most common number B1.1, deals with dimensions and thread tolerances; B1.2 with gages and their use; B1.3 with various systems for gaging threads; B1.7 with definitions of terms.

ANTI-FRICTION COATING (AF) - AF coating are dry lubricants consisting of suspensions of solid lubricants, such as graphite, PTFE, or molybdenum disulphide of small particle size in a binder. Such coatings can be applied to fastener threads to replace metallic coatings such as zinc and cadmium and offer maintenance free permanent lubrication. By careful selection of the lubricants, AF coatings can be designed to meet specific applications. The coatings are permanently bonded to the metal surface and provide a lubricating film preventing direct metal to metal contact.

ANTI-SEIZE COMPOUND - An anti-seize compound is used on the threads of fasteners in some applications. The purpose of the compound depends upon the application. It can prevent galling of mating surfaces - such compounds are frequently used with stainless steel fasteners to prevent this effect from occurring. In some applications it is used to improve corrosion resistance to allow the parts to be subsequently dis-assembled. Thirdly, it can provide a barrier to water penetration since the threads are sealed by use of the compound.

ANVIL - The head or tail of the fastener which is in contact with the outer surface of the joint material.

ANVIL - The part of an installation tool nose assembly used to swage the collar of a lockbolt fastener. Commonly known as a swaging anvil.

APPLIED FORCE - A measure of the user applied force as the screw is installed. More force is not necessarily better.

APPLIED LOAD - Force or moment transferred across a joint; it does not include preload or changes in preload as a result of temperature change. (NOTE: APPLIED LOAD is also referred to in literature as External load, Externally Applied Load or Service Load)

ARBOR - That portion of a lathe carriage that contains the clutches, gears, and levers for moving the carriage. It also protects the mechanism.

AS FORGED - The condition of a forging as it comes out of the finisher cavity without any subsequent operations.

ASD - Allowable Stress Design (According to the AISC 9th Ed.)

ASME - American Society of Mechanical Engineers. The organization is known for setting codes and standards for mechanical devices.

ASSEMBLY - A unit of fitted parts that make up a mechanism or machine.

ASTER RECESS - The ASTER recess was designed by LISI Aerospace to provide a more reliable solution than the hexagonal recess for assemblies on composite structures on aircraft. The recess is optimized to fit on the threaded end of aerospace fasteners. These fasteners allow for tightening the nut and holding the bolt simultaneous, on the same side of the structure, by only one operator.

ASTM - Specifications Standards developed by the American Society for Testing and Materials.

ASTM 193-194 - ASTM 193 are chemical and physical specifications for hex hex cap screw, studs, and bolts made of steel and stainless steel. ASTM 194 refers to nuts. The commonly used stainless is called grade 8, referring to 304 material to certain specifications, and grade 8M referring to 316 material. The major differences between ASTM and commercial stainless fasteners are: (a) 304 material must be used for manufacturing grade 8, not simply 18-8: (b) ASTM generally refers to heavy hex head and heavy nuts, though semi-finished hex heads and finished nuts may be supplied with the permission of the buyer; (c) cold formed material will require carbide solution treatment or annealing to reduce hardness to meet ASTM requirements.

ASTM F1941 - This the standard specification for electrodeposited coatings on threaded fasteners. This plating specificatin is recommended when determining the proper application, performances and dimensional requirements for electrodeposited coatings on threaded fasteners.

ATHREADED INSERT - An insert for installation into sheet material where a receptacle for a male-threaded component is required.

AUSTEMPERING - A patented heat-treating process that consists of quenching an iron based alloy from a temperature above the transformation range in a medium having a high rate of heat abstraction, and then maintaining the metal until transformation is complete, at a substantially uniform temperature which is below that of pearlite formation and above that of martensite.

AUSTENITE - A solid combination of iron and at least one alloying element defined by a cubic crystal structure that is face-centered. Most common engineering steels transform into pearlite, bainite, or martensite during the austenite phase when factoring in the cooling rate.

AUSTENITE - A phase in steels which consists of the gamma form of iron with carbon in solid solution. Austenite is tough, non-magnetic and tends to work-harden rapidly when cold worked in those steels which are austenitic at ordinary temperatures. A specific metallic solution of steel that allows for higher carbon absorption. Austenite exists in the temperature range of approximately 1341 F (727C) to 2719 F (1493C). It is non-magnetic, has the crystal structure of face-centered cubic.

AUSTENITIC - Refers to 300 series stainless steel, the most popular of the stainless alloys accounting for 85%-90% of stainless fasteners sold. Named for Sir Robert Williams Austen, an English metallurgist, austenitic stainless is a crystal structure formed by heating steel, chromium and nickel to a high temperature where it forms the characteristics of 300 series stainless steel. An AUSTENITE is a molecular structure where 8 atoms of iron surround one atom of carbon, thus limiting the corrosive effects of the carbon. Austenitic fasteners have the highest level of corrosion resistance in the stainless family, cannot be hardened by heat treatment, and are non-magnet for practical proposes. The most popular of austenitic grades is known generically as 18-8 stainless, and grades 302, 302HQ, 303, 304, 305, and XM-7. Typical industries using 18-8 stainless fasteners include: food, dairy, wine chemical, pulp and paper, pharmaceutical, boating swimming pools, pollution control, electronic, medical and hospital equipment, computer, and textile. Type 316 stainless has added nickel and especially molybdenum. The molybdenum (called moly) sharply increases corrosion resistance to chlorides and sulfates, including various sulfurous acids in the pulp industries has superior tensile strength at high temperatures compared to 18-8. Besides pulp and paper, typical industries using 316 are: photographic and other chemicals, ink, textile, bleach, rubber. Exotic metals in the 300 series include 309, 310, 317, 321, and 347. With superior resistance at elevated temperatures, these metal are used for furnace parts, high temperature containers and processing equipment, aircraft parts such as collector rings, exhaust systems, and equipment for very corrosion compounds of sulfuric, nitic, citric and lactic acids.

AUSTENITIC STEEL - A steel which has a stable austenitic structure at normal (room) temperatures, or 300 series, stainless steels. They contain a maximum of 0.15 percent carbon, a minimum of 16 percent chromium and sufficient nickel and/or manganese to retain an austenitic structure at all temperatures from the cryogenic region to the melting point of the alloy.

AUSTENIZING - The process of uniformly hearing a metal until the grain structure transforms from Ferrite to Austenite. For carbon steels, transformation begins at approximately 1341 degrees F and becomes completely uniform throughout the metal at a higher temperature (varies by carbon content).

AUTOCATALYTIC PLATING - Deposition of a metallic coating by a controlled chemical reduction that is catelyzed by the metal or alloy being deposited.

AUXILIARY OPERATIONS - Additional processing steps performed on forgings to obtain properties, such as surface conditions or shapes, not obtained in the regular processing operation.

AVERAGE COATING THICKNESS - This is determined as either the value obtained by analytical methods or the mean value of a specified number of local thickness measurements that are evenly distributed over the significant surface.

AWS - American Welding Society

AXIAL LOAD - Force applied through the axis of a fastener or structure.

AXIAL ROLLS - In ring rolling, vertically displaceable, tapered rolls, mounted in a horizontally displaceable frame opposite from but on the same centerline as the main roll and rolling mandrel. The axial rolls control the ring height during the rolling process.

AXIS/AXIS OF THREAD - Axis of the pitch cylinder.

AXISYMMETRIC FORGING - A forging where metal flow, during deformation, is predominately in a direction away from a common axis in a radial direction.