Both surface finish and surface integrity must be defined, measured, and maintained within specified limits in the processing of any product. Surface texture is defined in terms of roughness, waviness, lay, and flaws. This article illustrates some of the designations of surface roughness and the symbols for defining lay and its direction. In addition, it describes the applications of surface integrity, typical surface integrity problems created in metal removal operations, and principal causes of surface alterations produced by machining processes. The article tabulates the effect of some machining methods on fatigue strength, and low-stress grinding procedures for steels, nickel-base high-temperature alloys, and titanium alloys.

This article focuses on precision and ultraprecision finish machining techniques that make use of defined cutting edges, such as polycrystalline diamond and cubic boron nitride compacts. The techniques are finish turning, finish broaching, finish milling, and finish drilling.

This article describes the use of conventional machining techniques, laser cutting and water-jet cutting for producing finished composite parts. It explains two representative polymer-matrix composites--graphite and aramid composites--and discusses the machining and drilling problems such as delamination and fiber or resin pullout. The article describes machining and drilling techniques and the necessary tools and cutting parameters. It presents a description of laser cutting. The article also provides information on the advantages, disadvantages, cutting characteristics, and applications of water-jet cutting and abrasive water-jet cutting.

Machining is a term that covers a large collection of manufacturing processes designed to remove unwanted material, usually in the form of chips, from a workpiece. This article discusses the basic classes of machining operations, including conventional, abrasive, and nontraditional, and outlines the type of costs incurred by the process. It describes the types of machining equipment, including general-purpose machine tools, production machining systems, and computer numerically controlled machining systems. The article lists the common classes of metallic work materials, in order of decreasing machinability. It also shows the range of dimensional and surface finish tolerances in graphical form that can be achieved using various machining processes under general machining conditions.

The design of forging operations; consisting of dies, fixturing, and parts; requires a consistent and unambiguous method for representing critical dimensions and tolerances. This article presents a dimensioning process, based on tooling points and datum planes, with the potential to simplify geometries while minimizing tolerance stack-ups. The method also facilitates inspection liaison between vendors and users because fixturing is easy to duplicate and tooling points are consistent from forging to finish-machined part. The article focuses on the most common dimensional tolerances for closed-die forgings, including finish allowances for machining, length and width tolerances, die-wear tolerance, match tolerances, die-closure or thickness tolerances, straightness and flatness tolerances, radii tolerances, flash-extension tolerances, and surface tolerances. It also contains a convenient summary in the form of a checklist.

Mass finishing normally involves loading components to be finished into a container together with abrasive media, water, and compound. This article focuses on basic mass finishing processes, including barrel finishing, vibratory finishing, centrifugal disc and barrel finishing, spindle finishing, and drag finishing. It describes the various factors considered in selecting the most suitable mass finishing process. The article also provides information on consumable materials, process considerations, safety precautions, and waste disposal of mass finishing processes.

This article is a comprehensive collection of machining data, presented in tables, covering most of the commonly used machining operations including turning, face milling, end milling (peripheral), drilling, reaming, and tapping of several materials. It provides starting recommendations for the range of speeds and feeds for various machining operations, parameters for the selection of tool geometry, and guidelines on the selection and identification of cutting fluids.

This article is a comprehensive collection of summary charts that provide data and information that are helpful in considering and selecting applicable processes alternative to the conventional material-removal processes. Process summary charts are provided for electrochemical machining, electrical discharge machining, chemical machining, abrasive jet machining, laser beam machining, electron beam machining, ultrasonic impact grinding, hydrodynamic machining, thermochemical machining, abrasive flow machining, and electrical discharge wire cutting.

Fundamental to the machining process, is the metal-cutting operation, which involves extensive plastic deformation of the work piece ahead of the tool tip, high temperatures, and severe frictional conditions at the interfaces of the tool, chip, and work piece. This article explains that the basic mechanism of chip formation is shear deformation, which is controlled by work material properties such as yield strength, shear strength, friction behavior, hardness, and ductility. It describes various chip types, as well as the cutting parameters that influence chip formation. It also demonstrates how the service life of cutting tools is determined by a number of wear processes, including tool wear, machining parameters, and tool force and power requirements. It concludes by presenting a comprehensive collection of formulas for turning, milling, drilling, and broaching, and its average unit power requirement.

Porcelain enamels are glass coatings applied primarily to products or parts made of sheet steel, cast iron, and aluminum to improve appearance and to protect the metal surface. This article describes the types of porcelain enamels, and details enamel frits for these materials. It provides a list of steels suitable for porcelain enameling and discusses the most important factors considered in the selection of steel for porcelain enameling. The article briefly presents the preparation methods of these materials for porcelain enameling and covers the methods, and furnaces of porcelain enameling. It examines the role of coating thickness, firing time and temperature, metal substrate, and color on the performance of enameled surfaces. The article concludes with a discussion on the properties of enameled surfaces, factors considered in process control, and test procedures for evaluating the quality of enameled surfaces.

Rotary swaging is an incremental metalworking process for reducing the cross-sectional area or otherwise changing the shape of bars, tubes, or wires by repeated radial blows with two or more dies. This article discusses the applicability of swaging and metal flow during swaging. It describes the types of rotary swaging machines, auxiliary tools, and swaging dies used for rotary swaging and the procedure for determining the side clearance in swaging dies. The article presents an overview of automated swaging machines and tube swaging, with and without a mandrel. It analyzes the effect of reduction, feed rate, die taper angle, surface contaminants, lubrication, and material response on swaging operation. The article discusses the applications for which swaging is the best method for producing a given shape, and compares swaging with alternative processes. It concludes with a discussion on special applications of swagging.

This article describes the applications, advantages, and disadvantages of three centrifugal casting processes as well as the equipment used. The processes include true centrifugal casting (horizontal, vertical, or inclined) semicentrifugal (centrifugal mold) casting, and centrifuge mold (centrifugal die) casting. The article discusses the cooling, inoculation, fluxing, and extraction of casting. It reviews mold heating and coating techniques as well as various molds used for the centrifugal casting processes. The three most common defects observed in centrifugal castings are also discussed. The article concludes with information on the applications of centrifugal force in investment casting and combustion synthesis.

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.

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.

This article reviews the methods of machining and finishing forging dies. It illustrates different stages in die manufacturing. The article provides a brief description on requirements and characteristics of high-speed machining tools, including feed rates, spindle speed, surface cutting speeds, and high acceleration and deceleration capabilities. It discusses electrodischarge machining process and electrochemical machining process. The article concludes with information on die-making methods.

Nontraditional finishing processes include electrochemical machining (ECM), electrodischarge machining (EDM), and laser beam machining. These processes belong to nonabrasive finishing methods where surface generation occurs with an insignificant amount of mechanical interaction between the processing tool and the workpiece surfaces. This article provides information on the equipment used, applications, process capabilities, and limitations of ECM and EDM.

After solidification and cooling, further processing and finishing of the castings are required. This article describes the general operations of shakeout, grinding, cleaning, and inspection of castings, with particular emphasis on automation technology. It illustrates the vertical core knockout machine and the A-frame core knockout machine and lists the advantages and disadvantages of the knockout machines. The article describes the general factors in automated or manual gate removal process. It concludes with discussion on the various types of inspection, such as liquid penetrant inspection, pressure testing, radiographic inspection, magnetic particle inspection, and ultrasonic inspection.

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.

Aluminum or aluminum alloy products have various types of finishes applied to their surfaces to enhance appearance or improve functional properties. This article discusses the procedures, considerations, and applications of various methods employed in the cleaning, finishing, and coating of aluminum. These include abrasive blast cleaning, barrel finishing, polishing, buffing, satin finishing, chemical cleaning, chemical brightening, electrolytic brightening, chemical etching, alkaline etching, acid etching, chemical conversion coating, electroplating, immersion plating, electroless plating, porcelain enameling, and shot peening.

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.