This article discusses the mill products most often formed by the three-roll forming process. It schematically illustrates some of the shapes commonly produced from flat stock by the three-roll forming process. The article describes the two basic types of three-roll forming machines, namely, the pinch-roll type and the pyramid-roll type. It also lists the advantages of the pinch-roll machine, as compared to the pyramid-roll machine. The article analyzes the hot forming and cold forming processes for carbon or low alloy steel. It explains the procedure for forming truncated cones, bars, and bar sections by utilizing the pyramid-roll machine.

This article describes various bending methods: draw bending, compression bending, roll bending, stretch bending, and ram-and-press bending. It discusses the machines used for the bending of bars. These machines include devices and fixtures for manual bending, press brakes, conventional mechanical and hydraulic presses, horizontal bending machines, rotary benders, and bending presses. The article illustrates the tools used in bending and other bending process. It also tabulates the lubricants required for bending specific metals.

Thread rolling is a cold-forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Methods that use cylindrical dies are classified as radial infeed, tangential feed, through feed, planetary, and internal. This article focuses on the capabilities, limitations, and machines used for these methods. It describes the three characteristics, such as rollability, flaking, and seaming, used in evaluating and selecting metals for thread rolling. The article explores the factors affecting die life and explains the effect of thread form on processing. It provides information on various fluids used in thread rolling to cool the dies and the work and to improve the finish on the rolled products. The article provides a comparison between thread rolling and cutting, as well as between thread rolling and grinding.

This article discusses the three characteristics that are important in evaluating and selecting metals for thread rolling, namely, rollability, flaking, and seaming. It reviews the capabilities and limitations of flat-die rolling, radial-infeed rolling, tangential rolling, through-feed rolling, planetary thread rolling, continuous rolling, and internal thread rolling, as well as the rolling machines and dies used. The article describes the factors affecting die life and provides information on radial die load, seam formation, surface finish, and thread dimensions that are affected by the form of the thread. It explains the reasons for using fluids in thread rolling. The article concludes with a comparison of rolling with cutting and grinding.

This article describes the operation procedures of wire rolling in a Turks Head machine. It discusses spring coiling, as well as the manual and power bending used in the wire forming process. The article contains a table that lists examples of several wire-forming production problems and solutions. Lubricants for wire forming such as inorganic fillers, soluble oils, and boundary lubricants are reviewed. The article also analyzes the applications of lubricants in wire forming.

Contour roll forming is a continuous process for forming metal from sheet, strip, or coiled stock into desired shapes of uniform cross section by feeding the stock through a series of roll stations equipped with contoured rolls. This article discusses the materials, roll-forming machines, tooling, and auxiliary equipment used in contour roll forming and its process variables. Tooling used in roll forming includes forming rolls and dies for punching and cutting off the material. The article discusses the additional tooling required in tube mills to weld, size, and straighten the tubes as they are produced on the machine. It describes the roll design for tube rolling and reviews the seam welding operations of pipe and tubing. The article discusses cross-sectional tolerances, the reshaping of round tubing, and factors that affect the quality, accuracy, and surface finish.

Roll forging is a process for simultaneously reducing the cross-sectional area and changing the shape of heated bars, billets, or plates. This article provides an overview of the process capabilities, production techniques, machines and machine size selection considerations, and types of roll dies and auxiliary tools for the roll forging. It concludes with information on the production examples of roll forging.

Ring rolling is a process for creating seamless ring shaped components using specialized equipment and forming processes. This article provides information on the applications of ring rolling. It discusses the types of machines used for ring rolling, namely, vertical rolling machines, radial-axial horizontal rolling machines, four-mandrel mechanical table mills, three-mandrel table mills, and automatic radial-axial multiple-mandrel ring mills. The article provides a discussion on the process control technology and ancillary operations of ring rolling. It describes the methods of producing ring blanks and the various types of blanking and rolling tools used in ring rolling process. The article concludes with a discussion on rolled ring tolerances and machining allowances.

Metalworking is one of the three major technologies used to fabricate metal products. This article tabulates the classification of metal forming processes. It discusses different types of metalworking equipment, including rolling mills, ring-rolling machines, and thread-rolling and surface-rolling machines. The article outlines the significant characteristics of pressing-type machines: load and energy characteristics, time-related characteristics, and accuracy characteristics. It summarizes different specialized processes such as advanced roll-forming methods, equal-channel angular extrusion, incremental forging, and microforming. The article describes the thermomechanical processing of nickel- and titanium-base alloys and concludes with information on the advancements in process simulation.

This article describes the roll forming of components of nickel, titanium, and aluminum alloys. The metallurgical characteristics of the roll formed components, such as macrostructures, microstructures, tensile strength, and stress rupture performance, are discussed. The article compares the resulting properties of roll formed and conventionally forged components.

This article discusses the mechanics, surface preparation and principles of metal forming operations such as drawing, bending (draw bending, compression bending, roll bending, and stretch bending), spinning, and straightening of bars, tubes, wires, rods and structural shapes. The article also discusses the machines and tools, including dies and mandrels, and lubricants used for these metal forming operations.

Thermoforming is a manufacturing process in which thermoplastic sheets are heated, softened, clamped onto a mold, and made to conform to the shape of the mold or forming tool. It is ideally suited to large-volume runs of small items. This article focuses on major phases of thermoforming, namely, sheet transportation, heating, forming/cooling, and trimming, and different thermoforming techniques: basic female forming; basic male forming; matched-mold thermoforming; plug-assist thermoforming; pressure bubble plug-assist vacuum thermoforming; vacuum snapback thermoforming; air-slip thermoforming; and trapped-sheet, contact heat, and pressure thermoforming. It concludes with a discussion on machines and the economic concerns of thermoforming.

The multiple-slide machine, sometimes called a four-way, four-slide, or multislide machine, is a somewhat specialized item of stamping equipment, although it is very versatile within a limited area of stamping applications. This article discusses the construction and advantages of multiple-slide machines. It presents comparisons of four-slide operations with press operations based on production speed, tooling cost, tool adjustments, and operating cost. The article reviews some factors to be considered while selecting multiple-slide machines. It summarizes the strip materials commonly used in four-slide production. The article examines the design factors of four-slide parts, including tolerances and finishes. It provides the design recommendations for optimal part quality at maximum production speed. The article also discusses various four-slide cutoff methods.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

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 is a comprehensive collection of terms related to metalworking operations that produce shapes from forging, extrusion, drawing, and rolling operations.

Rolling-contact fatigue (RCF) is a surface damage process due to the repeated application of stresses when the surfaces of two bodies roll on each other. This article briefly describes the various surface cracks caused by manufacturing processing faults or blunt impact loads on ceramic balls surfaces. It discusses the propagation of fatigue cracks involved in rolling contacts. The characteristics of various types of RCF test machines are summarized. The article concludes with a discussion on the various failure modes of silicon nitride in rolling contact. These include the spalling fatigue failure, the delamination failure, and the rolling-contact wear.

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.

This article is a compilation of definitions of the terms related to sheet metal forming and fabrication.