Induction hardening is a prominent method in the gear manufacturing industry due to its ability of selectively hardening portions of a gear such as the flanks, roots, and/or tips of teeth with desired hardness, wearing resistance, and contact fatigue strength without affecting the metallurgy of the core. This article provides an overview of gear technology and materials selection. It describes different gear-hardening patterns, namely, tooth-by-tooth hardening, tip-by-tip hardening, gap-by-gap hardening, spin hardening, single-frequency gear hardening, dual-frequency gear hardening, simultaneous dual-frequency gear hardening, and through heating for surface hardening. It provides information on the different inspection methods based on the American Gear Manufacturers Association, revealing metallurgical data, hardness, and dimensions of gears. In addition, the article presents a comparative study on the mechanical properties of contour-hardened and carburized gears. It concludes by describing typical failures of induction-hardened steels and the corresponding prevention methods.

Flame hardening is a heat treating process in which a thin surface shell of a steel part is heated rapidly to a temperature above the critical temperatures of the steel. The versatility of flame-hardening equipment and the wide range of heating conditions obtainable with gas burners, often permit flame hardening to be done by a variety of methods. These include the spot or stationary method, progressive method, spinning method, and the combination progressive-spinning method. This article provides information on fuel gases used in flame hardening and their selection criteria for specific applications. It also discusses operating procedures and control requirements for flame hardening of steel.

Metal spinning is a term used to describe the forming of metal into seamless, axisymmetric shapes by a combination of rotational motion and force. This article describes two forming techniques, such as manual spinning and power spinning, for forming seamless metal components. The process technology, equipment, and tooling for both manual spinning and power spinning are also discussed.

This article tabulates the nominal compositions for nickel and cobalt alloys. It illustrates the comparison of strain-hardening rates of a number of alloys in terms of the increase in hardness with increasing cold reduction. The forming practice for age-hardenable alloys and the lubricants used in the forming processes of nickel and cobalt alloys are also discussed. The article summarizes the modification of tools and dies used for cold forming other metals, as the physical and mechanical properties of nickel and cobalt alloys frequently necessitate it. It discusses forming techniques for these alloys and provides several examples of these techniques, which include shearing, blanking, piercing, deep drawing, spinning, explosive forming, bending, and expanding/tube forming.

This article discusses the mechanics, surface preparation and principles of metal forming operations such as drawing, bending (draw bending, compression bending, roll bending, and stretch bending), spinning, and straightening of bars, tubes, wires, rods and structural shapes. The article also discusses the machines and tools, including dies and mandrels, and lubricants used for these metal forming operations.

This article discusses the selection of types of stainless steel for various methods of forming based on the formability and on the power required for forming. It reviews the requirements of lubrication, blanking, and piercing. The article describes various forming methods, namely, press-brake forming, press forming, multiple-slide forming, deep drawing, spinning, rubber-pad forming, drop hammer forming¸ three-roll forming, contour roll forming, stretch forming, and bending of tubing.

This article discusses the fundamentals and applications of localized heat treating methods: induction hardening and tempering, laser surface transformation hardening, and electron-beam heat treatment. The article provides information about equipment and describes the selection of frequency, power, duration of heating, and coil design for induction hardening. The article also discusses the scope, application, methods, and operation of flame hardening.

This article reviews the general characteristics of copper and copper alloys and explains how these characteristics affect the behavior of strip in different types of forming operations. These forming operations include blanking, piercing, bending, drawing and stretch forming, spinning, rubber-pad forming, and contour roll forming. Specialized forming operations such as hydraulic forming, embossing and swaging, and high-velocity metal forming are also reviewed. The article discusses the forming of smaller and larger parts from copper and copper alloy strips, as well as their property requirements and applications.

This article introduces process factors that influence die wear and lubrication for metal forming operations such as bending, spinning, stretching, deep drawing, and ironing. It discusses the effects of part shape, sheet thickness, tolerance requirements, sheet metal, and lubrication on shallow forming dies. The article describes the wear of material for dies to draw round and square cup-shaped metal parts in a press. It also discusses the effect of process conditions on the shallow forming dies.

This article discusses the general formability considerations of aluminum alloys. To conduct a complete analysis of a formed part, the required mechanical properties, as determined by several standard tests, must be considered. The article describes tension testing and other tests designed to simulate various production forming processes, including cup tests and bend tests, which help in determining these properties. It provides information on the equipment and tools, which are used in the forming of aluminum alloys. The article presents a list of lubricants that are most widely used in the forming. It also analyzes the various forming processes of aluminum alloys. The processes include blanking and piercing, bending, press-brake forming, contour roll forming, deep drawing, spinning, stretch forming, rubber-pad forming, warm forming, superplastic forming, explosive forming, electrohydraulic forming, electromagnetic forming, hydraulic forming, shot peening, and drop hammer forming.

This article introduces the general principles and applications of heat treatment to iron castings. It provides a detailed discussion on the heat treatment processes, namely, stress relieving, annealing, normalizing, throughhardening, and surface hardening for various types of cast irons. These include gray iron, ductile iron, compacted graphite iron, white iron, malleable iron, and high-alloy iron. The article describes how to control temperature and atmosphere during the heat treatment of the iron castings.

In terms of forming, magnesium alloys are much more workable at elevated temperatures due to their hexagonal crystal structures. This article describes the deformation mechanisms of magnesium and provides information on the hot and cold forming processes of magnesium alloys and the lubricants used in the processes. It discusses the various forming processes of magnesium alloys. These include press-brake forming, deep drawing, manual and power spinning, rubber-pad forming, stretch forming, drop hammer forming, and precision forging.

Characteristics of stainless steel that affect its formability include yield strength, tensile strength, and ductility, in addition to the effect of work hardening on these properties. This article discusses the forming process of stainless steel, heat-resistant alloys and refractory metals, detailing the major aspects of forming, including formability, lubrication, and forming methods and tools. The effect of factors such as alloy condition, cold reduction, forming direction (in the case of heat-resistant alloys) and temperature (in the case of refractory metals) on formability is also discussed.