Aluminum products such as fasteners and automotive components are often produced by cold extrusion because it facilitates high volume production of near-net-shape parts. This article describes the cold extrusion process for aluminum alloys and the associated requirements for tooling, dies, punches, and other equipment. It covers typical tool materials and their working properties, and provides best practices for sizing aluminum slugs and preparing them for use. The article also discusses the wide range of achievable shapes from shallow cup-like extrusions to deep cups and complex parts with longitudinal flutes, stems, and grooves.

Cold extrusion is a push-through compressive forming process with the starting material (billet/slug) at room temperature. This article provides information on the different types of steels that can be cold extruded. Mechanical presses and hydraulic presses that are specifically designed for cold extrusion with high rigidity, accurate alignment, and long working strokes are described. The article details the factors that are critical in cold extrusion: punch design, die design, and tool design. It summarizes the role of lubricants during extrusion of steel, such as soap lubricant and polymer lubricants. The article describes several procedures for extruding specific steel parts such as tubular parts and stepped shafts. It lists problems such as tool breakage and galling or scoring of tools and explains cold extrusion of aluminum, copper, and nickel alloy parts. The article also discusses the impact extrusion of magnesium alloys.

This article describes die wear and failure mechanisms, including thermal fatigue, abrasive wear, and plastic deformation. It summarizes the important attributes required for dies and the properties of the various die materials that make them suitable for particular applications. Recommendations on the selection of the materials for hot forging, hot extrusion, cold heading, and cold extrusion are presented. The article discusses the methods of characterizing abrasive wear and factors affecting abrasive wear. It discusses various die coatings and surface treatments used to extend the lives of dies: alloying surface treatments, micropeening, and electroplating.

Wire rod is a semifinished product rolled from billet on a rod mill and is used primarily for the manufacture of wire. Steel wire rod is usually cold drawn into wire suitable for further drawing; for cold rolling, cold heading, cold upsetting, cold extrusion, or cold forging; or for hot forging. The article explains these operations, along with the several recognized quality and commodity classifications applicable to steel wire rods. The heat treatments commonly applied to steel wire rod, either before or during processing into wire, include annealing, spheroidize annealing, patenting, and controlled cooling. When the end product must be heat treated, the heat treatment and mechanical properties should be clearly defined. Carbon steel rods are produced in various grades or compositions: low-carbon, medium-low-carbon, medium-high-carbon, and high-carbon steel wire rods. Rod for the manufacture of carbon steel wire is produced with manufacturing controls and inspection procedures intended to ensure the degree of soundness and freedom from injurious surface imperfections necessary for specific applications. This article also describes the various quality descriptors applicable to the rods as well as standard qualities and commodities available in alloy steel wire rod.

Fine-blanking is a hybrid metal forming process that combines the technologies of stamping and cold extrusion. This article describes the three principal design features of the fine blanking process: the vee-ring, clearance between punch and die, and counterforce imposed by the ejector. It discusses the advantages and disadvantages of edge blanking and materials. The article reviews the classification of fine-blanking dies such as the moving-punch system and the fixed-punch system, and provides information on the mechanical and hydraulic fine-blanking presses.

This article discusses two basic forms of extrusion: cold and hot. It provides information on three types of extrusion processes, namely, direct extrusion, reverse extrusion, and hydrostatic extrusion. The article also discusses the mechanics, analysis, tooling and die design of extrusion as well as thermodynamics. The finite-element method suitable for simulation of metal forming processes is explained. The article examines the extrusion defects that are divided into three different categories including surface, subsurface, and internal type. It includes information on friction and lubrication modeling of extrusion processes. The article also discusses the fundamentals of extrusion technology of titanium alloys and aluminum. It concludes with information on two forms of wear in extrusion, namely, adhesive and abrasive wear.

Cold heading is typically a high-speed process where a blank is progressively moved through a multi-station machine. This article discusses various cold heading process parameters, such as upset length ratio, upset diameter ratio, upset strain, and process sequence design. It describes the various components of a cold-heading machine and the tools used in the cold heading process. These include headers, transfer headers, bolt makers, nut formers, and parts formers. The article explains the operations required for preparing stock for cold heading, including heat treating, drawing to size, machining, descaling, cutting to length, and lubricating. It lists the advantages of the cold heading over machining. Materials selection criteria for dies and punches in cold heading are also described. The article provides examples that demonstrate tolerance capabilities and show dimensional variations obtained in production runs of specific cold-headed products. It concludes with a discussion on the applications of warm heading.

Aluminum and aluminum alloys are very suitable for extrusion and many types of profiles can be produced from easily extrudable alloys. This article lists the basic characteristics of aluminum and its alloys. It tabulates the aluminum extrusion alloys by series and lists the typical applications for 6xxx series aluminum extrusions. The article discusses three broad categories of extrusion profiles: solid profile, hollow profile, and semi hollow profile. It provides information on weldability and machinability, which are often considered in profile design and product performance. The article discusses different aluminum extrusion processes, such as the direct extrusion process and the indirect extrusion process. It schematically illustrates the plotting of flow stress and extrudability for several types of aluminum alloys. The article concludes with information on the heat treatment and precipitation hardening for alloys, such as 2xxx, 6xxx, and 7xxx.

Forging machines use a wide variety of hammers, presses, and dies to produce products with the desired shape, size, and geometry. This article discusses the major types of hammers (gravity-drop, power-drop, high speed, and open-die forging), and presses (mechanical, hydraulic, screw-type, and multiple-ram). It further discusses the technologies used in the design of dies, terminology, and materials selection for dies for the most common hot-forging processes, particularly those using vertical presses, hammers, and horizontal forging machines. A brief section is included on computer-aided design in the forging industry. Additionally, the article reviews specific characteristics, process limitations, advantages, and disadvantages of the most common forging processes, namely hot upset forging, roll forging, radial forging, rotary forging, isothermal and hot-die forging, precision forging, and cold forging.