Lapping is the lower-pressure, lower-speed, and lower-power application of the use of fixed abrasives. This article begins with a discussion on the process capabilities of lapping and reviews the selection of abrasive and vehicle for lapping. It describes the methods of lapping outer cylindrical surfaces, namely, ring lapping, machine lapping between plates, centerless roll lapping with loose abrasives, and centerless lapping with bonded abrasives. In addition, the article discusses the methods employed for lapping of outer surfaces of piston rings, crankshafts, inner cylindrical surfaces, flat surfaces, end surfaces, spherical surfaces, balls, spring like parts, and gears. It also reviews the problems in flat and end lapping. The article concludes information on the use of lapping in accelerated wearing-in process for matching and aligning components of bearing assemblies.

Metal is removed from the workpiece by the mechanical action of irregularly shaped abrasive grains in all grinding operations. This article discusses three primary components of grinding wheels, namely, abrasive (the cutting tool), bond (the tool holder), and porosity or air for chip clearance and/or the introduction of coolant. It describes the compositions and applications of coated abrasives and types of grinding fluids, such as petroleum-base and mineral-base cutting oils, water-soluble oils, synthetic fluids, semisynthetic fluids, and water plus additives. The article concludes with information on different types of grinding processes, namely, rough grinding, precision grinding, surface grinding, cylindrical grinding, centerless grinding, internal grinding, and tool grinding.

Ceramics usually require some form of machining prior to use to meet dimensional and surface quality standards. This article focuses on abrasive machining, particularly grinding, and addresses common methods and critical process factors. It covers cylindrical, centerless, and disk grinding and provides information on tooling, wheel selection, work material, and operational factors. It also discusses precision slicing and slotting, lapping, honing, and polishing as well as abrasive waterjet, electrical discharge, laser, and ultrasonic machining.

In all grinding operations, care must be used in the selection of wheels and abrasive belts to meet finish and tolerance requirements without damaging the workpiece. This article discusses the major aspects of the grinding wheel, including production methods, selection considerations, standard marking systems, abrasives, and bonding types. It compares bonded wheel grinding with abrasive belt grinding. The article reviews the types of grinding fluids and discusses their importance in grinding operations. It describes the specific grinding processes and provides recommendations for grinding and grinding wheels.

This article describes the sectioning process, some general practices, common tools, and guidelines on how to select a cutting tool for a given metallographic sectioning operation. It provides a discussion on the consumable-abrasive cutting and nonconsumable-abrasive cutting methods for metallographic sectioning. Other methods, including the use of hacksaws, shears, burning torches, wire saws, and electrical discharge machining, are also reviewed. The article reviews the issues related to the specimen test location for certification work as well as process troubleshooting and component failure analysis.

This article describes the various characteristics of electrochemical grinding (ECG). It discusses grinding methods that can be performed with ECG components, namely, the electrolyte delivery and circulating system, the electrolyte, the DC power supply, grinding wheel, and the workpiece. Grinding, surface grinding, internal grinding, form grinding, and cylindrical grinding are discussed. The article also lists the advantages, disadvantages, and applications of ECG.

Honing serves an important purpose of generating specified functional characteristics for surfaces besides removing stock and involves the correction of errors resulting from previous machining operations. This article discusses the process capabilities of honing in terms of bore size, bore shape, and stock removal. It illustrates the uses of air, ring, expanding, plug, and bar gages for automatic size control in power stroking of honing tools. The article provides a short description of various honing processes, such as external honing, gear tooth honing, plateau honing, flat honing, electrochemical honing, and hone forming. It also examines various process parameters in microhoning and concludes with information on the applications of microhoning.

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.

Finishing refers to a wide variety of processes that generally involve material removal in one form or another to generate surfaces with specific geometries, tolerances, and functional or decorative characteristics. This article discusses four major finishing methods, namely, abrasive machining, electropolishing, mass finishing, and shot peening. In each case, it describes subtypes, process variations, and the associated equipment.

This article provides a discussion on a working principle, the operations, characteristics, capabilities, and applications of electrochemical grinding (ECG). The basic elements of the ECG machine tool are also presented.

Abrasive jet machining (AJM) is a process that removes material from a workpiece through the use of abrasive particles entrained in a high-velocity gas stream. This article discusses the operation of principal components, advantages, and disadvantages of the AJM system. It describes several factors that determine the characteristics of the AJM process. These include flow rates of the jet stream, type and size of abrasive powders, and distance between the workpiece and nozzle.

This article discusses the principles of grinding process. It illustrates a typical wheel-work characteristic chart relating surface finish, wheel wear rate, metal removal rate, and power to the normal force. The article also reviews the effect of variations in work material, wheel specification, wheel speed, coolant, and grinding wheel-work conformity on the slopes of the wheel-work characteristic chart.

Mechanical cleaning systems are used to remove contaminants of work surface by propelling abrasive materials through any of these three principal methods: airless centrifugal blast blade- or vane-type wheels; compressed air, direct-pressure dry blast nozzle systems; or compressed-air, indirect-suction (induction) wet or dry blast nozzle systems. This article focuses on the abrasive media, equipment, applications, and limitations of dry and wet blast cleaning. It discusses the health and safety precautions to be taken during mechanical cleaning.

Superabrasives collectively refer to the diamond and cubic boron nitride (CBN) abrasives used in grinding applications. This article discusses the classification of superabrasive wheels according to a variety of sizes and shapes, construction, concentration, and bond systems. It provides information on the applications of the superabrasive wheels depending on the factors of the grinding system. These factors include machine tool variables, work material, wheel selection, and operational factors. The article describes the methods available for superabrasive wheel truing in production grinding operations, namely, stationary tool, powered, and form truings. It reviews the truing methods, such as truing with abrasive wheels and hard ceramics, for batch production. The article explains practical methods available for dressing CBN wheels, namely, abrasive stick, abrasive-jet, slurry, and high-pressure waterjet dressing. It concludes with information on the conditioning process of the CBN wheel.

Metallographic analysis is primarily a collection of visual and imaging techniques that provide an insight into the background of a material or part and its behavior. Metallic specimens, both porous and pore-free, are opaque, and as a result, an optical examination must be performed on carefully prepared planar (two-dimensional) surfaces. This article discusses the preparation sequence of ferrous powders, which is normally separated into several well-defined steps: sample selection, sectioning, mounting, grinding, polishing, drying, and chemical etching and/or coating. It provides several suggestions to promote and encourage the safety of those performing metallographic preparation and analysis.

Impact wear can be defined as the wear of a solid surface that is due to percussion, which is a repetitive exposure to dynamic contact by another solid body. This article discusses the volume (or mass) removal of material either at or under engineering contact stress levels and outlines a rational, semi-empirical impact wear theory. It illustrates a linear wear mechanism that occurs in print heads and repetitive impacts that take place in metallic machine contacts. The article concludes with information on plotting a wear curve for an originally plane, massive carbon steel machine platen subjected to repetitive compound impact by a hard, nonwearing spherical-ended steel alloy component.

Wear is mechanically-induced surface damage that results in the progressive removal of material. Because different types of wear occur in machinery, many different types of wear tests have been developed to evaluate its effects on materials and surface treatments. This article provides an explanation on mechanisms, forms (sliding, impact, and rolling) and the causes of wear. It describes the wear measuring methods, including the mass loss method, wear width method, and scar depth method. The units used to report wear vary with type of wear and with the purpose for which the data are to be used. Listing the considerations of tribosystem analysis, the article provides information on selection of ASTM wear test methods grouped by wear type. The article concludes by tabulating the testing geometries and parameters that are commonly controlled and reported when conducting wear tests.

Abrasive wear is a surface-damage process with material loss caused by hard asperities or abrasive particles occurring when two surfaces are sliding against each other. There are two types of abrasive wear: two-body abrasion and three-body abrasion. This article discusses the abrasive wear mechanism in ductile materials and commonly used testers for evaluating the resistance of materials to abrasive wear. The testers include pin-on-disk, block-on-ring, block-on-drum, and dry sand/rubber wheel abrasion tester. The article reviews the abrasion resistance of metallic materials, ceramic materials, and polymeric materials. It discusses factors that influence abrasive wear, including the environment, hardness, toughness, microstructure, and lubrication.

This article describes the secondary operations for cemented carbide parts, namely, diamond grinding, honing, electrical discharge machining, and brazing after sintering to achieve desired results, such as specified size, shape, edge condition, and surface finish.