Cores are separate shapes of sand that are placed in the mold to provide castings with contours, cavities, and passages that are not otherwise practical or physically obtainable by the mold. This article describes the basic principles of coremaking and the types of core sands, binders, and additives used in coremaking. It discusses the curing of compacted cores by core baking and the hot box processes. The article provides an overview of core coatings, assembling and core setting, coring of tortuous passages, and cores in permanent mold castings and investment castings. It also discusses the design considerations in coremaking to eliminate cores and compares coring with drilling.

Cores are separate shapes, of sand, metal or plaster, that are placed in the mold to provide castings with contours, cavities, and passages. Cored holes should be designed as simply as the intended function of the casting permits. This article describes the designing of casting for the use of sand cores and to eliminate cores, with illustrations. It provides general rules for designing cored holes in investment castings. The article discusses the general principles of coremaking with illustrations. It concludes with a comparison between coring and drilling.

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 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.

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.

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.

This article provides a useful guide for measuring residual macrostress on coatings. The most commonly used measurement methods are mechanical deflection, X-ray diffraction, and hole-drilling strain-gage. After a discussion on the origins of residual stress, the article describes the fundamental principles and presents examples of practical measurements for each method.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of high-carbon steels and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the following: torsional fatigue fracture, hydrogen-embrittlement fracture, fatigue crack propagation, and corrosion fatigue of components made from high-carbon steels. The high-carbon steel components include bull gear, drive shaft, power boiler stoker grate, steel wheel, spring wire, suspension spring, automotive engine valve spring, power spring, cantilever-type spring, railroad rail, and seamless drill pipe.

Engineered components fail predominantly in four major ways: fracture, corrosion, wear, and undesirable deformation (i.e., distortion). Typical fracture mechanisms feature rapid crack growth by ductile or brittle cracking; more progressive (subcritical) forms involve crack growth by fatigue, creep, or environmentally-assisted cracking. Corrosion and wear are another form of progressive material alteration or removal that can lead to failure or obsolescence. This article primarily covers the topic of abrasive wear failures, covering the general classification of wear. It also discusses methods that may apply to any form of wear mechanism, because it is important to identify all mechanisms or combinations of wear mechanisms during failure analysis. The article concludes by presenting several examples of abrasive wear.

This article discusses the classifications, specifications, applications and methods for producing welded and seamless steel tubular products, including pipes and tubes. Common types of pipes include standard pipe, conduit pipe, piling pipe, pipe for nipples, transmission or line pipe, water main pipe, oil country tubular goods, water well pipe, and pressure pipe. Pipes in suitable sizes, and most of the products classified as tubing, both seamless and welded, may be cold finished. Pressure tubes are given a separate classification by both the American Society for Testing and Materials (ASTM) and producers. The term tube covers three groups, including pressure tubes, structural tubing, and mechanical tubing.

An understanding of the influence of microstructure on machinability can provide an insight into more efficient machining and the correct solution to problems. Providing numerous microstructures to depict examples, this article describes the relationship between the microstructure and machinability of cast irons, steels, and aluminum alloys. It presents data on hardness values and the effect of the matrix microstructure of cast iron on tool life. It also explains how a higher inclusion count improves the machinability of steels and why aluminum alloys can be machined at very high speeds.

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.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of gray irons and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the fatigue fracture, solidification structure, and crack propagation of gray irons.

Cutting fluids play a major role in increasing productivity and reducing costs by making possible the use of higher cutting speeds, higher feed rates, and greater depths of cut. After listing the functions of cutting fluids, this article then covers the major types, characteristics, advantages and limitations of cutting and grinding fluids, such as cutting oils, water-miscible fluids, gaseous fluids, pastes, and solid lubricants along with their subtypes. It discusses the factors considered during the selection of cutting fluid, focusing on machinability (or grindability) of the material, compatibility (metallurgical, chemical, and human), and acceptability (fluid properties, reliability, and stability). The article also describes various application methods of cutting fluids and precautions that should be observed by the operator.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of copper alloys and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the following: fatigue fracture, intergranular fracture, transgranular fracture, microvoid coalescence, corrosion fatigue, fatigue striations, tensile-overload fracture, stress-corrosion cracking, and pitting corrosion of these alloys.

The concept of surface integrity for grinding operations can be extended to encompass six different groups of key factors: visual, dimensional, residual stress, tribological, metallurgical, and others. This article discusses the importance of these factors in the performance and behavior of finishing methods in various manufactured parts. Special emphasis is given to residual stresses and their influence on the final mechanical properties of a manufactured part.

The presence of macroscopic residual stresses in heat treatable aluminum alloys can give rise to machining distortion, dimensional instability, and increased susceptibility to in-service fatigue and stress-corrosion cracking. This article details the residual-stress magnitudes and distributions introduced into aluminum alloys by thermal operations associated with heat treatment. The available technologies by which residual stresses in aluminum alloys can be relieved are also described. The article shows why thermal stress relief is not a feasible stress-reduction technology for precipitation-hardened alloys. It examines the consequences of aging treatments on the residual stress, namely, annealing, precipitation heat treatment, and cryogenic treatment. The article provides information on uphill quenching, which attempts to reverse thermal gradients encountered during quenching. It examines how quench-induced residual stresses in heat treatable aluminum alloys are reduced when sufficient load is applied to cause plastic deformation. The article also shows how plastic deformation reduces residual stress.

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 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.