McGuire Glossary of Fastener Terminology

W - 66 terms

WAFER HEAD - A countersunk head with a flat top surface and a cone-shaped bearing surface. The wafer's 70 degree conical under the head area does not extend to the outer edge of the head, providing a bearing surface of 16 degrees around the circumference of the under head. Preferred head style for Type CSD self-drilling screws. Provides the necessary bearing surface and flush fit in wood and softer materials. The head/shank fillet is contoured to strengthen the under head area.

WAHL FACTOR (SPRING TERM) - A factor to correct stress in helical springs that accounts for the effects of coil curvature and direct shear.

WAISTED SHANK BOLT - A bolt whose diameter is less than the minor diameter of the thread. Frequently the shank of the bolt is 0.9 times the root diameter.

WALL THICKNESS - The thickness of meta, per side, between the shank diameter and the counterbore diameter.

WARM FORGING - Deformation at elevated temperatures below the recrystallization temperature. The flow stress and rate of strain hardening are reduced with increasing temperature; thus, lower forces are required than in cold working. For steel, the temperature range from about 1000 degrees F to just below the normal hot working range of 1900 to 2300 degrees F.

WARM FORMING - A special metal forming process where the incoming wire or re-fed blank is heated to an elevated temperature to reduce the forming load and increase ductility.

WARPAGE - Term generally applied to distortion that results during quenching from heat-treating temperatures; hand straightening, press straightening, or cold restriking is employed, depending on the configuration of the part and the amount of warpage involved. The condition is governed by applicable straightness tolerances; beyond tolerances, warpage is defect and cause for rejection. The term is not to be confused with bend or twist.

WASHER - A part, usually thin, having a centrally located hole or partial slot. The washer performs various functions when assembled between the bearing surface of a fastener and the part being attached. Insulation, lubrication, spanning of large clearance holes, and improved stress distribution are a few of the design uses.

WASHER FACE - A circular boss on the bearing surface of a hex head cap screw or a hex nut to provide a flat bearing surface for the hex head cap screw or hex nut.

WASHER HEAD - A head having a circular collar with a large flat bearing surface. Common head styles are Hex Washer, Round Washer, Hex Flange and special configurations.

WASPALOY - This Nickel based alloy which delivers strength and reliability at extreme temperatures as high as 1600 F/ 870 C. Waspaloy derives its high-temperature strength from a soldi solution of molybdenum, cobalt and chromium, and its age-hardening elements aluminum and titanium. Missile systems ad gas turbine blades are common applications.

WASTE - The metal used in excess of that required for the finish part.

WASTE - All overproduction ahead of demand, waiting for the next processing step, unnecessary transport of materials, excessive inventories, unnecessary employee movement, and production of defective parts.

WATER BREAK - The appearance of a discontinuous film of water on a surface signifying non-uniform wetting and usually associated with a surface contamination.

WATER SPIDER - An individual who performs a wide range of tasks which allow for other workers to perform value-added tasks.

WATER-BASED ADHESIVES - Adhesives that work through the evaporation or adbsorption of water in the adhesive by the substrate.

WATERFALL PUNCH - A special design backward extrusion punch with a partial spherical nose shape and no extrusion land.

WAVE SOLDER - Prcocess of applying product to PCB by placding product on a solder pad and running the board over a fountain of solder that wicks up along an exposed length of product on the opposing side of the PCB. Parts using this technology would be special products with modified design.

WAVE THREAD™ - The basic wave thread is an expanding stack of circles with their centers following a helical path. That helical path generates the wave on the surface. Patent Issued

WAVO - Single turn round wire wave spring.

WAX - Used for ease of assembly. Standard plating for thread rolling screws and locknuts.

WAYS - The fitted V-shaped grooves in the ram and columns of a hammer or press that guide the descent and ascent of the ram.

WBS - An acronym meaning work breakdown structure. This activity expands an improvement project into a detailed listing of activities.

WCM (WORLD CLASS MANUFACTURING) - The philosophy of being the best, the fastest, and the lowest cost producer of a product or service in order to remain an industry leader.

WEB - A relatively flat, thin portion of a forging, generally parallel to the forging plane - that connects ribs and bosses.

WEBS - Material between two openings or edges. The thin material to be punched

WEDGE - An adjustable machine part mounted on the heading slide behind the tooling. Wedge adjustment moves the tooling closer or farther away from the face of die at front dead center. Used to control the length dimensions of the formed parts.

WEDGE & AXIAL TENSILE TESTING - Axial and wedge tensile testing is done to determine the behavior of materials under axial tensile loading. Axial tests are performed by securing the fastener into the testing machine and then applying force to the fastener by separating the testing apparatus crossheads. The wedge test is also an axial test. The difference is that a wedge is placed under the head during testing to see if the head of the fastener can withstand the added stress of the torque load caused by the wedge. The wedge tensile test is usually done on square or hex head fasteners and socket head cap screws.

WEDGE ANCHOR - Made of a steel rod that is threaded on one end and the other end has a diameter necked down for a short distance that tapers outwardly to the full diameter of the rod. A clip is permanently preassembled in this space. The anchor is installed in a pre-drilled hole and set by tightening the nut by torqueing, thereby causing the expansion clip to expand over the tapered mandrel to engage the base material. A wedge anchor may also be referred to as a torque controlled expansion anchor.

WEDGE HEAD - A style of insert, usually thin wall, that has a number of wedge shaped protrusions added at the intersection of the head and shank to increse spin-out from sofer materials. Can also be used to improve the eletrical connection between the insert and the panel for current carrying applications.

WEDGE TENSILE TEST - An axial test, except a wedge is placed under the head during the testing. The procedure that induces a bending stress under the head of a bolt, used to demonstrate ductility and the integrity of the head-to-shank junction.

WELDING - A joining process that uses heat, pressure and/or chemicals to fuse two materials together permanently.

WET BLASTING - A process for cleaning or finishing by means of a slurry of abrasive in water directed at high velocity against the work pieces.

WETTING AGENT - A substance that reduces the surface tension of a liquid, thereby causing it to spread more readily on a solid surface.

WHEELABRATING - Shot blasting with steel grit or shot thrown from a spinning wheel patented by Wheelabrator Fyre.

WHISKERS - Metallic filamentary growths, often microscopic, sometimes formed during electro-deposition and sometimes spontaneously during storage or service, after finishing.

WHISTLE NOTCH - An angle machined cut in the side of a tool or die case that accepts the hold down screw from the tool holder or die block.

WHITWORTH THREAD - A screw thread, also known as the British Standard Whitworth (B.S.W.), used principally in Great Britain.

WINDING - High-speed process of twisting spring tempered wire into a helix by machines specially designed for such an operation.

WIP (WORK-IN-PROESS) - Inventory that exists in batches between workstations.

WIPE DIE - Forming tool using two opposing edges, separated by one material thickness, moving past each other to form material.

WIRE - ALUMINUM KILLED - The most uniform commercial quality wire having a consistent structure throughout the entire cross-section.

WIRE - ANNEALED - Produces improved ductility to a lesser degree than spheroidizing.

WIRE - BRIGHT STEEL - A wire with a very thin lime coating only. Suitable for heading and threading but not extruding.

WIRE - COLD EXTRUSION COATING - A coating that must be suitable for at least two extrusion operations.

WIRE - COLD EXTRUSION QUALITY - Exceptionally ductile wire with surface defects kept to a minimum.

WIRE - COLD HEADING QUALITY - Wire satisfactory for the forming of trimmed hex head or square head bolts.

WIRE - RECESSED HEAD QUALITY - Wire to be used for the forming of high strength socket head screws, recessed head screws and similar parts.

WIRE - RIMMED - A wire with an outer rim that is low in carbon and manganese with a core of higher carbon and manganese content. This produces a very ductile rim. Widely used in heading of low carbon fasteners.

WIRE - SPHEROIDIZE -ANNEAL-IN-PROCESS - A heat treating operation between two drawing operations to produce a high quality wire with maximum ductility.

WIRE DRAWER - A device in the wire line of the machine before the feed rolls/grips. It reduces the diameter of the incoming wire. It can be either an inline wire drawer powered by the cold forming machine or a stand alone capstan type with it's own drive mechanism. This allows the use of larger toleranced hot rolled rod which can be drawn to specific diameters.

WIRE FORMING - Use of the latest CNC equipment to ensure accuracy of wire formed parts.

WIRE FORMING MANUFACTURING - Fabrication of a metal part, made from wire, on a slide forming machine

WIRE STRAIGHTENER - A device with multiple staggered opposing rolls used to remove the bends and kinks from the incoming wire.

WOBBLE - Defective condition in internally threaded products in which the threads are not perpendicular to the bearing service.

WORK CELL - The layout of machines or business processes of different types, performing different operations in a tight sequence, (typically a U-Shape or L Shape) to permit single piece flow and flexible deployment of human effort.

WORK CENTER - One process station in a work cell.

WORK HARDENING - Strength increase resulting from the permanent plastic deformation of a metal at a temperature below its recrystallization point, low enough to produce strain hardening.

WORK HARDENING - Deforming metal to the point at which it can increase in hardness and strength is exhibited. Also known as Strain Hardening.

WORK HARDNESS - Hardness and strength developed in metal because of cold working. Also known as Strain Hardening.

WORK MATERIAL HARDNESS - The material's hardness resistance to drilling or cutting. In most instances, the harder the material, the more difficult it is to cut.

WORK STROKE - The distance that the heading slide moves to perform a specific forming operation.

WORM THREADS - A screw thread used with a mating wormgear, helical gear, spur gear or rack to reduce speed, increase torque. Worms are generally used on shafts mounted at 90 degrees. Worm threads are not standardized but are in popular pitch series such as Diametral Pitch, Circular Pitch and Metric Module Pitch.

WR - Wide Root provides the strongest UNR thread form and with the greatest opportunity to maximize fatigue resistance.

WRENCHING HEAD - A head having provision for driving or holding by means of a wrench. 'External Wrenching' designates the application of a wrench externally to the sides of the head. 'Internal Wrenching' designates the application of a wrench internally to a socket, the sides of which are parallel to the fastener axis.

WROUGHT STEEL - A descriptive term for any particle of steel that has been produced by hot mechanical working.