Abrasive finishing is a method where a large number of multipoint or random cutting edges are coupled with abrasive grains as a bond or matrix material for effective removal of material at smaller chip sizes. This article provides a broad overview of the various categories of abrasive products and materials, abrasive finishing processes, and the mechanisms of delivering the abrasives to the grinding or machining zone. Abrasive finishing processes, such as grinding, honing, superfinishing, microgrinding, polishing, buffing, and lapping, are discussed. The article presents a brief discussion on abrasive jet machining and ultrasonic machining. It concludes with a discussion on the four categories of factors that affect the abrasive finishing or machining: machine tool, work material, wheel selection, and operational.

Ring rolling is a process for creating seamless ring shaped components using specialized equipment and forming processes. This article provides information on the applications of ring rolling. It discusses the types of machines used for ring rolling, namely, vertical rolling machines, radial-axial horizontal rolling machines, four-mandrel mechanical table mills, three-mandrel table mills, and automatic radial-axial multiple-mandrel ring mills. The article provides a discussion on the process control technology and ancillary operations of ring rolling. It describes the methods of producing ring blanks and the various types of blanking and rolling tools used in ring rolling process. The article concludes with a discussion on rolled ring tolerances and machining allowances.

Hammers and high-energy-rate forging machines are classified as energy-restricted machines as they deform the workpiece by the kinetic energy of the hammer ram. This article provides information on gravity-drop hammers, power-drop hammers, die forger hammers, counterblow hammers, and computer-controlled hammers. It describes the three basic designs of high-energy-rate forging (HERF) machines: the ram and inner frame, two-ram, and controlled energy flow. The article reviews forging mechanical presses, hydraulic presses, drive presses, screw presses, and multiple-ram presses.

Metalworking is one of the three major technologies used to fabricate metal products. This article tabulates the classification of metal forming processes. It discusses different types of metalworking equipment, including rolling mills, ring-rolling machines, and thread-rolling and surface-rolling machines. The article outlines the significant characteristics of pressing-type machines: load and energy characteristics, time-related characteristics, and accuracy characteristics. It summarizes different specialized processes such as advanced roll-forming methods, equal-channel angular extrusion, incremental forging, and microforming. The article describes the thermomechanical processing of nickel- and titanium-base alloys and concludes with information on the advancements in process simulation.

This article discusses the significant factors in the selection of forging equipment for a particular process. It describes the characteristics of forging hydraulic presses, mechanical presses, screw presses, and hammers. The article discusses the significant characteristics of these machines that comprise all machine design and performance data, which are pertinent to the economic use of the machines, including the characteristics for load and energy, time-related characteristics, and characteristics for accuracy.

This article focuses on the various technology drivers for finishing methods, namely, tolerance, consistency, surface quality, and productivity. Every finishing method may be viewed as a manufacturing system consisting of four input categories: machine tool, processing tool, work material, and operational factors. The article provides a classification of finishing as a surface generation process and addresses the characteristics of the generated surfaces and the methods used to measure them. It describes the thermomechanical interactions occurring between the processing tool and the work material in the presence of machine tool and operational factors.

Forging machines use a wide variety of hammers, presses, and dies to produce products with the desired shape, size, and geometry. This article discusses the major types of hammers (gravity-drop, power-drop, high speed, and open-die forging), and presses (mechanical, hydraulic, screw-type, and multiple-ram). It further discusses the technologies used in the design of dies, terminology, and materials selection for dies for the most common hot-forging processes, particularly those using vertical presses, hammers, and horizontal forging machines. A brief section is included on computer-aided design in the forging industry. Additionally, the article reviews specific characteristics, process limitations, advantages, and disadvantages of the most common forging processes, namely hot upset forging, roll forging, radial forging, rotary forging, isothermal and hot-die forging, precision forging, and cold forging.

Roll forging is a process for simultaneously reducing the cross-sectional area and changing the shape of heated bars, billets, or plates. This article provides an overview of the process capabilities, production techniques, machines and machine size selection considerations, and types of roll dies and auxiliary tools for the roll forging. It concludes with information on the production examples of roll forging.

This article discusses the operation of upset forging machines and selection of the machine size. It describes several types of upsetter heading tools and their materials. The article reviews the cold shearing and hot shearing methods for preparing blanks for hot upset forging. It deals with various upsetting processes: offset upsetting, double-end upsetting, upsetting with sliding dies, upsetting pipe and tubing, and electric upsetting. The article also provides information on hot forging and cold forging.

Filament winding is a process that allows the precise lay-down of continuous reinforcement in predescribed patterns at a high rate of speed. This article discusses the filament winding process and includes a comparison to other compacting and curing processes. The article describes design factors, and techniques to produce aerodynamic surfaces, improve surface smoothness, and avoid slipping and bridging of filament. The article discusses tooling and the equipment used in the filament winding process, namely, mandrel design, winding machines, tensioners, and ovens.

Radial forging is a hot- or cold-forming process that uses two or more radially moving anvils or dies to produce solid or tubular components with constant or varying cross sections along their lengths. This article focuses on the workpiece configuration, workpiece materials, machines, dies, advantages, and limitations of radial forging. It concludes with a discussion on the applications of radial forging.

Radial forging is a process performed with four dies arranged in one plane that can act on a piece simultaneously. This article explains the types of radial forgings and describes the advantages and disadvantages of radial forging over open-die cogging/forging. The article discusses the parameters involved in product shape control. It also provides examples that illustrate the versatility and capabilities of the radial forge machine.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

Open-die forging can be distinguished from most other types of deformation processes in that it provides discontinuous material flow as opposed to continuous flow. This article describes the equipment and auxiliary tools used in open-die forging. It discusses the production and practice of open-die forging, with some practical examples. The article illustrates macrosegregation in a large steel ingot and lists the forgeable alloys. It reviews the physical and mathematical models used in deformation modeling. The article explains the contour forging and roll planishing process. It inform that to ensure that forgings can be machined to correct final measurements, it is necessary to establish allowances, tolerances, and specifications for flatness and concentricity. The article also tabulates the allowances and tolerances for as-forged shafts and bars.

Shell molding is used for making production quantities of castings that range in weight from a few ounces to approximately 180 kg (400 lb), in both ferrous and nonferrous metals. This article lists the limitations or disadvantages of shell mold casting. It describes the two methods for preparation of resin-sand mixture for shell molding, namely, mixing resin and sand according to conventional dry mixing techniques, and coating the sand with resin. Shaping of shell molds and cores from resin sand mixtures is accomplished in machines. The article discusses the major steps in producing a mold or core and describes the problems most frequently encountered in shell-mold casting. The problems include mold cracking, soft molds, low hot tensile strength of molds, peelback, and mold shift. The article concludes with information on examples that provide some relative cost comparisons between shell molding and green sand molding.

Thermoforming is a manufacturing process in which thermoplastic sheets are heated, softened, clamped onto a mold, and made to conform to the shape of the mold or forming tool. It is ideally suited to large-volume runs of small items. This article focuses on major phases of thermoforming, namely, sheet transportation, heating, forming/cooling, and trimming, and different thermoforming techniques: basic female forming; basic male forming; matched-mold thermoforming; plug-assist thermoforming; pressure bubble plug-assist vacuum thermoforming; vacuum snapback thermoforming; air-slip thermoforming; and trapped-sheet, contact heat, and pressure thermoforming. It concludes with a discussion on machines and the economic concerns of thermoforming.

This article focuses on the forging behavior and practices of carbon and alloy steels. It presents general guidelines for forging in terms of practices, steel selection, forgeability and mechanical properties, heat treatments of steel forgings, die design features, and machining. The article discusses the effect of forging on final component properties and presents special considerations for the design of hot upset forgings.

Structural applications for advanced ceramics include mineral processing equipment, machine tools, wear components, heat exchangers, automotive products, aerospace components, and medical products. This article begins with an overview of the wear-resistant applications and the parameters affecting wear of ceramics, namely, hardness, thermal conductivity, fracture toughness, and corrosion resistance. The next part of the article addresses temperature-resistant applications of advanced ceramics. Specific applications of ceramic materials addressed include cutting tools, pump and valve components, rolling elements and bearings, paper and wire manufacturing, biomedical implants, heat exchangers, adiabatic diesel engines, advanced gas turbines, and aerospace applications.

Passivation; pickling, that is, acid descaling; electropolishing; and mechanical cleaning are important surface treatments for the successful performance of stainless steel used for piping, pressure vessels, tanks, and machined parts in a wide variety of applications. This article provides an overview of the various types of stainless steels and describes the commonly used cleaning methods, namely, alkaline cleaning, emulsion cleaning, solvent cleaning, vapor degreasing, ultrasonic cleaning, and acid cleaning. Finishing operations of stainless steels, such as grinding, polishing, and buffing, are reviewed. The article also explains the procedures of electrocleaning, electropolishing, electroplating, painting, surface blackening, coloring, terne coatings, and thermal spraying. It includes useful information on the surface modification of stainless steels, namely, ion implantation and laser surface processing. Surface hardening techniques, namely, nitriding, carburizing, boriding, and flame hardening, performed to improve the resistance of stainless steel alloys are also reviewed.

This article presents a detailed account of the welding parameters, equipment needed, applications, advantages, limitations, and the process variables affecting various types of resistance welding operations, namely, resistance spot welding, resistance seam welding, resistance projection welding, and flash welding.