Glossary 869 Field windings: Two or more stationary, wire-wound magnets in a dc generator. Filler material: Material that is added to a weld to build it up. Filler metal: Metal that is added when making welded, brazed, or soldered joints. Filler passes: Passes put down between the hot pass and cover pass that fi ll up the weld joint in a multipass weld. Filler rod: A nonstandard term. See Welding rod. Filler wire: A nonstandard term. See Welding wire. Fillet weld: Metal fused into a corner formed by two pieces of metal whose welded surfaces are approximately 90° to each other. Fillet weld bend test: Test that requires a fi llet weld to be made on one side of a T-joint. The vertical piece is then bent over the weld until the weld fails or is bent fl at against the horizontal piece. Filter lenses: Lenses that protect the eyes from ultravi- olet, infrared, and visible radiation. They are typically green or brown and are available in a variety of shade intensities. Finish symbol: A symbol that indicates the method of fi nishing. Used only when the weld is not to remain in an “as welded” condition. Firebricks: Heat-resistant bricks or stones used to form welding table tops or to provide support to weldments. Fire watch: A person who carefully watches for fi res that may start in the area where welding or cutting is done. Fishtail: A repair in which the end of a large diameter pipe is prepared in a V-shape, and a smaller diameter pipe is inserted into it. A weld is created around the joint to join the pipes. Fitness for service: The concept that all welds contain fl aws. If the fl aws or discontinuities are too large, or there are too many of them, they will affect the perfor- mance of the weldment. Fixture: A device designed to hold a specifi c part and accu- rately locate it during production. Parts are often located in the fi xture by pins and held by clamps. Flame cutting: Cutting performed by an oxyfuel gas torch fl ame which has a second oxygen jet. Flame hardening: Surface-hardening method that uses a multiple-tipped oxyfuel fl ame. Flame spraying (FLSP) process: Process that sprays pure or alloyed metals onto a part or assembly. Surfacing or cladding materials are melted in an oxyfuel gas fl ame and carried to the surface of the part being surfaced in a fl ame or gas jet. Flange fi tting: A fi tting that is attached to a pipe at one end, and has a wide fl at collar on the other end. Flange joint: A joint that is formed when the edge of one or more pieces of the joint is bent to form a fl ange. Flared fi ttings: Threaded fi ttings that are installed over tubing, which is then fl ared to form a seal with the fi tting and hold it in place. Flare-groove joint: A joint formed when the fl anged edges of one or both pieces are placed together to form a single- fl are-bevel or double-fl are-V-groove. Flash: Impact of electric arc rays against the human eye. Also, the surplus metal formed at the seam of a resis- tance weld. Flashback: A burning back of the gases into the oxyfuel gas torch, hoses, and possibly into the regulator and cylinder. Flashback arrestor: A type of check valve, usually installed between torch and welding hose to prevent fl ow of burning fuel gas and oxygen mixture back into hoses and regulators. Flash butt welding: A process used to weld the ends of metal rods, rails, beams and other shapes together. Flashing: Expulsion of molten metal. Also, describes the formation of electric arcs between the closest points in oppositely charged irregular surfaces. Flash welding (FW): Process using electric arc in combina- tion with resistance and pressure welding. Flat (1G) welding position: A welding position in which the weld axis and weld face are horizontal. Flat position weld: A weld performed on a joint in the fl at welding position. Flaw: A discontinuity or change in the normal structure of a material. If a fl aw is larger than an acceptable limit, it becomes a defect. Flexible tubing: Tubing that can be easily bent to the shape needed. Flow switches: Devices used to verify gas or fl uid is fl owing through a pipe or tube. Flow temperature: The temperature at which all of a brazing alloy is liquid. Fluorescent dye: Dye that gives off or refl ects light when exposed to short-wave radiation. Fluorescent penetrant: Penetrating fl uid with a fl uorescent dye added to improve the visibility of discontinuities. Flux: Material used to prevent, dissolve, or help remove oxides and other undesirable surface substances. Flux cored arc welding (FCAW): Welding method in which heat is supplied by an arc between a hollow, fl ux-fi lled electrode and the base metal. Flux oxygen cutting: A nonstandard term. See Chemical fl ux cutting. Focal spot: In EBW and LBW, the spot where a beam’s energy level is most concentrated and where it has the smallest cross-sectional area. Force gauge: A device used to set the proper force on a spot welding gun. Forehand welding: Welding technique in which the tip of the electrode or torch is pointed in the direction of travel. Forge force: Additional pressure applied during the hold time to prevent aluminum or aluminum alloys from cracking while they are cooling. Forge welding (FOW): Welding process that joins two pieces of metal by heating them to a high temperature and then hammering them together. Forging: The process of making metallic shapes by either hammering or squeezing the original piece of metal. The resulting shape is also called a forging. Forming: Changing the shape of a metal part without changing its thickness.