The machinability of carbon and alloy steels is affected by many factors, such as the composition, microstructure, and strength level of the steel; the feeds, speeds, and depth of cut; and the choice of cutting fluid and cutting tool material. This article describes the influence of the various attributes of carbon and alloy steels on machining characteristics. It lists the relative machinability ratings for some plain carbon steels, standard resulfurized steels, and several alloy steels. The addition of lead to carbon steels is one of the means of increasing the machinability of the steel and improving the surface finish of machined parts. Low carbon content of carburizing steels may be beneficial to tool life and production rate. The sulfur content of through-hardening alloy steels can significantly affect machining behavior. Cold drawing generally improves the machinability of steels containing less than about 0.2% carbon.

The ultrasonic machining (USM) process consists of two methods, namely, ultrasonic impact grinding and rotary USM. This article lists the major ultrasonic components that are similar to both rotary USM and ultrasonic impact grinding. It also provides schematic representations of the components used in rotary USM and ultrasonic impact grinding. The article describes the operations of the components of the rotary ultrasonic machine and ultrasonic impact grinding machine. It discusses the applications of the rotary ultrasonic machine: drilling, milling, and surface grinding. The article concludes with information on machining characteristics of ultrasonic impact grinding.

The machinability of stainless steels varies from low to very high, depending on the final choice of the alloy. This article discusses general material and machining characteristics of stainless steel. It briefly describes the classes of stainless steel, such as ferritic, martensitic, austenitic, duplex, and precipitation-hardenable alloys. The article examines the role of additives, such as sulfur, selenium, tellurium, lead, bismuth, and certain oxides, in improving machining performance. It provides ways to minimize difficulties involved in the traditional machining of stainless steels. The article describes turning, drilling, tapping, milling, broaching, reaming, and grinding operations on stainless steel. It concludes with information on some of the nontraditional machining techniques, including abrasive jet machining, abrasive waterjet machining electrochemical machining, electron beam machining, and plasma arc machining.

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 focuses on the variety of alloys, furnaces, and associated melting equipment as well as the casting methods available for manufacturing magnesium castings. These methods include sand casting, permanent mold casting, die casting, thixomolding, and direct chill casting. The article discusses the flux process and fluxless process for the melting and pouring of magnesium alloys. It describes the advantages and disadvantages of green sand molding and tabulates typical compositions and properties of magnesium molding sands. The article provides information on the machining characteristics of magnesium and the applications of magnesium alloys.

The aluminum alloys 383.0, 384.0, and A384.0 are Al-Si-Cu high-strength die-casting alloys suitable for castings with thin walls and large areas. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and fabrication characteristics of these 3xxx series alloys.

Fabrication of wrought stainless steels requires use of greater power, more frequent repair or replacement of processing equipment, and application of procedures to minimize or correct surface contamination because of its greater strength, hardness, ductility, work hardenability and corrosion resistance. This article provides a detailed account of such difficulties encountered in the fabrication of wrought stainless steel by forming, forging, cold working, machining, heat treating, and joining processes. Stainless steels are subjected to various heat treatments such as annealing, hardening, and stress relieving. Stainless steels are commonly joined by welding, brazing, and soldering. The article lists the procedures and precautions that should be instituted during welding to ensure optimum corrosion resistance and mechanical properties in the completed assembly.

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.

The machinable high-strength alloy 6262 is a modification of the original alloy 6062 alloy with Pb and Bi additions to improve machinability. This datasheet provides information on composition limits, fabrication characteristics, processing effects on physical and mechanical properties, and applications of this 6xxx series alloy. Product specifications and heat treatments for this alloy are also listed.

The aluminum alloys 380.0, A380.0, and B380.0 are widely used for making general-purpose die castings. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, fabrication characteristics, and application characteristics of these 3xxx series alloys.

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.

The 443 series of aluminum casting alloys have nominal silicon content of 5 wt% with various limits on iron, copper, manganese and magnesium. They are hypoeutectic AI-Si binary alloys with high ductility, very good corrosion resistance, good machinability, but only fair castability, and low strength. The alloys are used in castings where above average ductility coupled with excellent corrosion resistance is needed. This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and application characteristics of these alloys.

Alloy 5254 is a higher-purity Al-Mg-Cr alloy used in heat exchangers, steam-jacketed kettles, and pumps. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and fabrication characteristics of this 5xxx series alloy.

The aluminum-tin alloys 850.0, 851.0, 852.0, and 853.0 are specialized compositions displaying excellent bearing characteristics under moderate loads and with effective lubrication. This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and application characteristics of these alloys. Permanent-mold aluminum casting rotating-beam fatigue curves for 850.0-T101, 850.0-T5, and 852.0-T5 alloys are also presented.

This article provides a comprehensive discussion on die casting alloy types and casting processes used in high-pressure die casting. It presents the advantages and disadvantages of high-pressure die casting and describes the product design for the process. The article concludes with information on the metal injection process of high-pressure die casting.

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.