Metalworking is, as its title suggests, working with metals to create individual parts. There is a wide range of technologies that are used within metalworking to create all types of products such as small pieces of jewelry all the way to building components and large-scale constructions. Most metalworking processes can be categorized into three categories: forming, cutting, or joining. However, it’s also important to note that casting is one of the most widespread methods of metalworking and involves pouring metal into a mold, after which is cooled and solidified. This guide will attempt to provide an overview of the most prevalent metalworking processes in the manufacturing industry today.
- Forming metal
- Metal bending
- Cutting metal
- Joining metal
- Metal casting
- What type of metalworking should be used?
Forming is the process of fashioning metal objects through deformation, without adding or removing any material. The process of deformation is performed using heat and mechanical loads. Forming also includes various manufacturing technologies like bending and forging.
Metal bending is a manufacturing process that uses ductile materials, most commonly sheet metal, as is generally used for equipment such as specialized machine presses. Metal bending is considered to be quite cost-effective for batches of low to medium quantity. Basically, there are three types of bending on a press brake: air bending (most common), bottoming and coining.
Forging is among the oldest metalworking processes. It uses local compressive forces for the shaping of metal. Nowadays, industrial forging is done with specialized pressing equipment (hammers), that can weigh more than thousands of pounds! One of the significant advantages of forging is that it can produce a part that is stronger than if it were made using casting or machining. The metal is shaped during the forging process, and its internal grain texture slowly deforms following the general shape of the part. After the process is complete, the finished product has vastly superior properties.
Cutting is a process during which material is given shape by removing some parts using tools. This process includes such technologies as CNC milling, routing and turning.
Machining is a collective title for various processes in which a piece of raw material is processed into a desired shape and size by computer-controlled tools. Such methods are often referred to as subtractive manufacturing, as opposed to additive manufacturing (3D printing) which builds a product from scratch. Machining is usually associated with the production of metal parts, but it is used with a wide range of materials including plastic, wood, composites, and more. The three primary machining processes are milling, routing and turning.
Operations in which a cutting tool rotates, bringing cutting edges to bear against a workpiece, are called milling. Milling machines are the principal machine tool used in milling.
CNC routing is similar to milling, with some CNC routing machines capable of performing almost the same tasks as that of milling machines. The primary functions are to cut, engrave and carve objects out of a workpiece - essentially a replacement for the usual hand-held router, but with the help of computer-controlled processes to eradicate human error.
Operations that rotate the workpiece as the primary method of moving metal against the cutting tool. Lathes are used in turning as the leading principal machine tool.
Joining means merging several parts of a metal product by processes like welding. Some metal 3D printing processes such as DMLS and EBM could also be called forms of welding.
Welding metal is a fabrication process that is based on joining materials via fusion which is a combination of pressure mixed with heat. In general, a filler material is added to form the welded joint, so that in some cases, can become even stronger than the original material. At the same time, the welding process must secure the filler metals/melted metals from being contaminated and/or oxidized. Welded operations can be categorized according to different energy sources that are used, among them are a gas flame, an electric arc, a laser, and ultrasound. Among the most popular welding methods include:
Oxy-fuel welding (oxy welding) that uses fuel gases and oxygen to weld and cut metals.
Shielded metal arc welding (electric welding) that uses an electrode that is coated in flux to protect the weld puddle. The electrode holder holds the wire as it slowly melts away.
Gas tungsten arc welding (inert gas) that uses a non-consumable tungsten electrode for producing the weld. However, the weld area has to be protected from atmospheric contamination by an inert shielding gas such as argon or helium.
Gas metal arc welding (inert gas) that uses a wire feeding gun that feeds wire at an adjustable speed and flows an argon-based shielding gas or a mix of argon and carbon dioxide (CO2) over the weld puddle to protect it from atmospheric contamination.
Metal casting is a metalworking process that is known to have started in ancient times, and it is still widely used for making sculptures, tools, and jewelry. Most popular methods include lost-wax casting and sand casting. They are subdivided by the mold material (e.g. sand or metal) and pouring method (such as gravity or vacuum).
What type of metalworking should be used?
Each metalworking process has its pros and cons - that’s why the manufacturing method should be chosen carefully. We recommend taking a closer look at each of the manufacturing processes in other manufacturing guides, and if necessary, contact us.