Search Results for extension wires

This article provides an in-depth review of thermocouples and the metals from which they are made. It explains how dissimilar metal conductors in contact at opposite ends can generate an electromotive force if the junctions are heated or cooled to different temperatures. The article discusses thermocouple circuits and instrumentation, calibration methods, insulation requirements, operating ranges, measurement errors, and maintenance procedures. It also provides property data and emf curves for common metals and thermocouple types, and contains information on color coding used around the world.

Steel springs are made in many types, shapes, and sizes, ranging from delicate hairsprings for instrument meters to massive buffer springs for railroad equipment. The primary focus of this article is small steel springs that are cold wound from wire. Wire springs are of four types: compression springs (including die springs), extension springs, torsion springs, and wire forms. Chemical composition, mechanical properties, surface quality, availability, and cost are the principal factors to be considered in selecting steel for springs. Both carbon and alloy steels are used extensively. The three types of wire used in the greatest number of applications of cold formed springs are hard-drawn spring wire, oil tempered wire and music wire. Residual stresses can increase or decrease the strength of a spring material, depending on their direction. Steel springs are often electroplated with zinc or cadmium to protect them from corrosion and abrasion. Although some hot-wound springs are made of steels that are also used for cold-wound springs, hot-wound springs are usually much larger, which results in significant metallurgical differences. All spring design is based on Hooke’s law; charts and formulas are available to aid in the design of springs.

Thermocouple devices are the most widely used devices for measurement of temperature in the metals industry. Favorable characteristics of these devices include good accuracy, suitability over a wide temperature range, fast thermal response, ruggedness, high reliability, low cost, and great versatility of application. Thermocouples are grouped into two broad categories, namely, standard thermocouples, including five base-metal thermocouples and three noble-metal thermocouples that have been given letter designations, and nonstandard thermocouples, including iridium-rhodium, platinum-molybdenum, platinel, and tungsten-rhenium thermocouples. This article discusses the basic principles, classification, and properties of thermocouples, and the techniques for insulating and protecting thermocouple wires from the operating environment.

Projection welding is a variation of resistance welding in which current flow is concentrated at the point of contact with a local geometric extension of one (or both) of the parts being welded. This article focuses on the process fundamentals, advantages, and limitations of projection welding and reviews the equipment used in the process. It discusses projection welding of copper and copper alloys, aluminum and aluminum alloys, and steels. The article provides several specifications and recommended weld schedules and practices for projection welding. It describes the embossed-projection welding of heavy-, intermediate-, and thin-gage sheet mild steel as well as the welds between dissimilar thickness joints. The article also considers the solid-projection welding of steels: annular, nut, and cross-wire projection configurations. It also details the various tests that can be used to validate projection weld quality.

Gas-metal arc welding (GMAW) is an arc welding process that joins metals together by heating them with an electric arc that is established between a consumable electrode (wire) and a workpiece. This article discusses the advantages and limitations, operating principle, metal transfer mechanisms, and process variables of the GMAW process. The process variables include welding current, polarity, arc voltage, travel speed, electrode extension, electrode orientation, and electrode diameter. The major components of the basic equipment for a typical GMAW installation are discussed. The article also describes two consumable elements, such as electrode and shielding gas, of the GMAW process. It concludes with information on the safety aspects.

Copper and copper alloys are used extensively in structural applications in which they are subject to moderately elevated temperatures. At relatively low operating temperatures, these alloys can undergo thermal softening or stress relaxation, which can lead to service failures. This article is a collection of curves and tables that present data on thermal softening and stress-relaxation in copper and copper alloys. Thermal softening occurs over extended periods at temperatures lower than those inducing recrystallization in commercial heat treatments. Stress relaxation occurs because of the transformation of elastic strain in the material to plastic, or permanent strain.

This article discusses the operation principles, advantages, limitations, process parameters, consumables or electrodes, the equipment used, process variations, and safety considerations of gas metal arc welding (GMAW). It reviews the important variables of the GMAW process that affect weld penetration, bead shape, arc stability, productivity, and overall weld quality. These include welding consumables, equipment settings, and gun manipulation. The major components of a GMAW installation such as a welding gun, shielding gas supply, electrode feed unit, power source, and associated controls are discussed.

Aluminum, the second most plentiful metallic element, is an economic competitor in various applications owing to its appearance, light weight, fabricability, physical properties, mechanical properties, and corrosion resistance. This article discusses the primary and secondary production of aluminum and classification system for cast and wrought aluminum alloys. It talks about various manufactured forms of aluminum and its alloys, which are classified into standardized products such as sheet, plate, foil, rod, bar, wire, tube, pipe, and structural forms, and engineered products such as extruded shapes, forgings, impacts, castings, stampings, powder metallurgy parts, machined parts, and metal-matrix composites. The article also reviews important fabrication characteristics in the machining, forming, forging, and joining of aluminum alloys. It concludes with a description of the major industrial applications of aluminum, including building and construction, transportation, consumer durables, electrical, machinery and equipment, containers and packaging, and other applications.

This article provides the basic physics of the two most widely used arc welding processes: gas tungsten arc welding and gas metal arc welding. It describes the various control parameters of these processes such as arc length control, voltage control, heat input control, and metal-transfer control.

Temperature control in heat treating is of paramount importance in maintaining the quality and achieving the desired metallurgical results. This article provides a detailed account of the factors affecting temperature control in heat treating furnaces, with information on temperature control systems, including contact sensors, noncontact sensors, controllers, energy-flow regulators, measurement instruments, and set-point programmers. Common contact sensors include temperature scales, thermocouples, and resistance temperature detectors, whereas optical pyrometers and on-line radiation thermometers fall under the noncontact type. The article describes two types of instrumentation used in heat treating: field test instruments for temperature-uniformity surveys and system-accuracy tests; and controlling, monitoring, and recording instruments for digital instrumentation.

Torch soldering utilizes a fuel gas flame as the heat source in the soldering process to produce a leak-tight assembly with some degree of mechanical strength. This article describes the advantages, limitations, and applications of torch soldering. It reviews the equipment used and the basic heating techniques required for the soldering.

Alloy 5056 can be used for nails and for redrawing rod to make wire. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and fabrication characteristics of this 5xxx series alloy.

This article discusses the failure mechanism of springs. It describes the critical application factors that affect spring fatigue performance. These include: material type and strength; stress conditions; surface quality; manufacturing processes; rate of application of load; and embrittlement or cracking. The article summarizes the methods of statistical analysis of S-N data for general comparisons of fatigue strength of spring steels. The fatigue performance of springs is illustrated by Goodman diagrams. The article also exemplifies the examination of failed springs.

Workability is the ability of the workpiece metal to undergo extrusion or drawing without fracture or defect development. This article describes the limits of workability in extrusion and drawing in terms of fracture and flaw development and presents some comments on fracture mechanisms. It discusses the empirical projections of absolute workability from various mechanical tests. The article concludes with a discussion on extrusion and drawing process design implications.

This article describes the operation procedures of wire rolling in a Turks Head machine. It discusses spring coiling, as well as the manual and power bending used in the wire forming process. The article contains a table that lists examples of several wire-forming production problems and solutions. Lubricants for wire forming such as inorganic fillers, soluble oils, and boundary lubricants are reviewed. The article also analyzes the applications of lubricants in wire forming.