This article discusses the different classes of gears, namely, spur, helical, herringbone, crossed-axes helical, worm, internal, rack, bevel, or face-type. It describes the methods used to cut the teeth of gears other than bevel gears: milling, broaching, shear cutting, hobbing, shaping, and rack cutting. The article also reviews the methods that are used to cut the teeth of bevel gears, such as face mill cutting, face hob cutting, formate cutting, helix form cutting, the Cyclex method, and template machining. The machining methods best suited to specific conditions are discussed. The article presents the factors influencing the choice of cutting speed and cutting fluids. It outlines two basic methods for the grinding of gear teeth: form grinding and generation grinding. The article concludes with information on the gear inspection techniques used to determine whether the resulting product meets design specifications and requirements.

Thread milling is a method of cutting screw threads with a milling cutter in a thread mill. This article discusses the operational procedures of thread milling machines, namely, universal thread mills, production thread mills, planetary thread mills, and numerical control machines. It describes the classification of thread milling cutters, such as single-form cutters and multiple-form cutters. The article reviews the speeds and feeds for thread milling, which depend on a number of variables, such as the material being milled, tool material, and rigidity of the machine and workpiece. It tabulates the cutting speeds for climb and conventional milling.

The horsepower requirements to cut various metal alloys provide an indication of the relative ease and cost of machining, but several other important factors include cutting tool material, chip formation, cutting fluids, cutting tool wear, surface roughness, and surface integrity. This article reviews these general machining factors as well as specific cutting tool and cutting parameters for the six basic chip-forming processes of turning, shaping, milling, drilling, sawing, and broaching. Best practices for each of the six chip-forming processes are suggested for optimized machining of aluminum alloys. The article lists the inherent disadvantages of machining processes that involve compression/shear chip formation. It discusses the machining of aluminum metal-matrix composites and nontraditional machining of aluminum, such as abrasive jet, waterjet, electrodischarge, plasma arc, electrochemical, and chemical machining.

This article begins with a discussion on machinability ratings of copper and copper alloys and then describes the factors influencing the machinability ratings. It explains the effect of alloying elements, cold working, and cutting fluid on the machinability of copper and copper alloys. In addition, the article provides a comprehensive discussion on various machining techniques that are employed for machining of copper and copper alloys: turning, planing, drilling, reaming, tapping and threading, multiple operation machining, milling, slitting and circular sawing, power band sawing and power hacksawing, grinding, and honing.

This article begins with a discussion on the classification of aluminum alloys and the selection of alloy and temper based on machinability. It provides an overview of cutting force and power, tool design and material, and general machining conditions. In addition, the article discusses distortion and dimensional variation and machining problems during the machining of high-silicon aluminum alloy. It also provides information on tool design and material, speed and feed, and the cutting fluid used for various machining processes, namely, turning, boring, planing and shaping, broaching, reaming, tapping, milling, sawing, grinding, honing, and lapping. The article concludes with a discussion on drilling operations in automatic bar and chucking machines and drill presses.

Nickel-base alloys can be machined by techniques that are used for iron-base alloys. This article discusses the effects of distortion and microstructure on the machinability of nickel alloys. It tabulates the classification of nickel alloys based on machining characteristics. The article describes the machining operations performed on nickel alloys, such as turning, planing and shaping, broaching, reaming, drilling, tapping and threading, milling, sawing, and grinding. It provides information on the cutting fluids used in the machining of nickel alloys. The article also analyzes nontraditional machining methods that are suitable for shaping high-temperature, high-strength nickel alloys. These include electrochemical machining, electron beam machining, and laser beam machining.

This article discusses the various elements of thread grinding processes, including thread grinding machines, tolerances, wheel selection, grinding speed, and grinding fluids. It describes truing of grinding wheels and reviews the process applications. In addition, the article describes the five basic methods employed for cylindrical thread grinding, namely, single-rib wheel traverse grinding, multirib wheel traverse grinding, multirib wheel plunge grinding, multirib wheel skip-rib, or alternate-rib, grinding, and multirib wheel three-rib grinding. It also provides an overview of centerless grinding of threads and high-volume applications of thread grinding.

This article focuses on machines that are designed, constructed, and used for drilling. It provides information on the design, materials, selection, and classification of drill. The article describes drills that are specially designed for hard steel and other specific applications. A variety of drill point styles, such as single-angle points and reduced-rake points, are described. The article discusses the factors considered to obtain expected dimensional accuracy of holes. It explains the determination of the optimum speed and feed for drilling, which depends on the workpiece material, tool material, depth of hole, design of drill, rigidity of setup, tolerance, and cutting fluid. The article illustrates the effects of operating variables on drill life of hardened steel. The advantages, limitations, design considerations, insert configurations, and applications of indexable-insert drills are discussed. The article concludes with a discussion on the requirements to drill small holes that differ from those used in conventional drilling.

This article discusses various machining techniques of zinc alloy die castings. These include turning, boring, drilling, reaming, tapping, die threading, milling, and sawing. In addition, the article describes the factors that influence machinability of the zinc alloy die castings.

This article describes the influence of steel chemical compositions and microstructure on machining processes. It discusses the various microstructural phases of standard carbon and alloy steels, which influence machinability. The article reviews the expected response of several traditional machining operations, such as turning, drilling, milling, shaping, thread cutting, and grinding, to the microstructure of standard steel grades. It also explains the technologies in non-traditional machining processes, such as abrasive waterjet cutting, electrical chemical grinding, and laser drilling.

This article presents general guidelines for machining metal matrix composites (MMC) and honeycomb structures. It provides guidelines for machining of specific MMCs, namely, aluminum-boron, aluminum-SiC, aluminum-Al 2 O 3 , and titanium-SiC MMCs. In addition, the article discusses the various parameters influencing drilling of dissimilar-material laminates.

Magnesium is machined in low-volume production on small, manually operated machine tools and on large, specially built, completely automated transfer machines operating at high production rates. This article focuses on the factors that affect the machining of magnesium. It discusses chip formation and distortion due to thermal expansion, cold work, and clamping and provides information on magnesium-matrix composites. The article describes materials, design, and sharpness as factors for selection of tool for machining magnesium. It illustrates turning and boring, planing and shaping, broaching, drilling, reaming, counterboring, milling, sawing, and grinding operations performed on magnesium. Safety measures related to machining, handling of chips and fines, and fire extinguishing are also discussed.

This article commences with a schematic illustration of a wide range of cutter configurations available for use in milling operations. It describes the various types of milling machines classified based on the type of construction, such as knee-and-column type, bed-type, planer-type, and special type. The article discusses mechanical-electric, mechanical-hydraulic, mechanical-electric-hydraulic, and numerical control of milling machines. It describes various types of milling cutters, such as peripheral mills, face mills, end mills, and special mills. Milling cutters, such as solid milling cutters, inserted-blade cutters, and indexable-insert cutters, are also discussed. The article explains the capabilities and limitations of peripheral milling, face milling, and end milling methods. It concludes with a comparison of milling with broaching, planing or shaping, and grinding.

This article describes the capabilities, limitations, advantages, and disadvantages of the powder metallurgy (PM) gear manufacturing process. It discusses the types of gears that can be produced by PM and presents the design guidelines for PM gears. The article provides information on gear tolerances and performance of PM gears. It also explains various procedures to inspect and test the mechanical properties, dimensional specifications, and surface durability (hardness).

This article begins with a discussion on the factors considered in the selection of bending methods. It presents a detailed description of the types of bending method, machines and tools used in the bending and forming of tubing. The article provides an overview of bending tubing with and without a mandrel and hot bending. It concludes with a discussion on the bending of thin-wall tubes and lubrication for tube bending.

This article provides a discussion on the machining guidelines that serve to improve the machinability of powder metallurgy materials. It provides a description of various cutting tool grades and tool-edge design and describes the machining conditions for common operations, namely, turning, drilling, tapping, grinding, and finishing. The article introduces a few overlooked details that can heavily influence the performance and success of the machining process. These include dwell, margin design on round tools, and proper edge hone.

Stretch forming is the forming of sheet, bars, and rolled or extruded sections over a die or form block of the required shape while the workpiece is held in tension. This article discusses the applicability, advantages, and machines and accessories of stretch forming. It provides a detailed discussion on four methods of stretch forming, namely, stretch draw forming, stretch wrapping, compression forming, and radial draw forming.

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.

Alloy 6013 is a high-strength Al-Mg-Si-Cu alloy, developed for extruded automotive bumpers. This datasheet provides information on key alloy metallurgy, processing effects on physical, tensile, static and fracture properties, and fabrication characteristics of this 6xxx series alloy.

Reaming is a machining operation in which a rotary tool takes a light cut to improve the accuracy of the round hole and reduce the roughness of the hole surface. This article describes its process capabilities and provides information on workpiece material and hardness, as well as the machines used. Reamer materials and design, speed and feed, bushings and fixtures, and cutting fluids used are also discussed. The article outlines the factors to be considered while selecting a reamer. It also discusses the applications of the principle types of reamers, namely, straight-flute chucking, spiral-flute chucking, adjustable, end-cutting, shell, floating-blade, gun, and special-purpose reamers, with examples.