Metal Forming: Principles, Processes, and Types Explained
Metal forming is the process of shaping metal into a finished geometry through mechanical deformation, without adding or removing material. Force from rolls, dies, or presses moves the metal past its yield point so it holds a new shape. Common in both sheet and section work, it produces repeatable parts with minimal scrap.
Among the many ways to change the shape of a piece of metal are bending and forming. Dating back to the Stone and Wood Ages, metalworking has long been associated with technical mastery and expertise. While its earliest uses were for creating cultural and ritualistic objects, the metal forming process has evolved over the years.
Significant developments have been made in the different types of metal forming processes. However, the basic principles of metal forming have remained the same, while the advantages of metal forming processes have increased.
What do you mean by metal forming?
Metal forming means reshaping solid metal into a target geometry by applying controlled force – through rolls, dies, or presses – rather than cutting or melting it. The metal is pushed past its yield point so the new shape holds. It covers the full discipline of metal forming, from plate rolling and section bending to forging and deep drawing.
What is the difference between forming and bending?
Metal fabrication is the umbrella term used for the classification of metal forming processes. Forming, bending, smelting, etc. all come under it. You might be wondering what the difference between bending and forming metal is. Well, even though they are both types of metal fabrication, bending is a subdivision of forming. Metal fabrication is like the tree trunk while forming is like one of the branches and bending is a twig on the forming branch. Other twigs in the forming branch include joining, dividing, coating, and modifying the material’s properties.
The availability of many different types of metal forming processes does not give a manufacturer the power to bend metal at will. There are standard procedures to follow. The forming and bending machines to be used, the right conditions, and the extent to which a piece of metal can be deformed is dictated by its properties. While some metals may be melted to be used in casting, others may need to just be heated up and reshaped using stamping methods.
What is the difference between forming and forging?
Forming reshapes metal by deformation across many processes – rolling, bending, drawing, extrusion. Forging is one of those processes: it hammers or presses metal, often hot, into a near-net shape. So all forging is forming, but not all forming is forging. Forming covers cold sheet and section work; forging targets high-strength, load-bearing parts.
Forming vs forging
| Metal forming (broad) | Forging (a sub-type) | |
|---|---|---|
| Scope | Any shaping by deformation | One forming process |
| Force | Rolls, dies, presses, brakes | Hammer / press, compressive |
| Temperature | Often cold (sheet / section) | Often hot |
| Typical output | Plates, cylinders, profiles, rings | High-strength near-net parts |
| Waste | Minimal – material reshaped | Minimal, plus preserved grain flow |
What are the main types of metal forming processes?
We can broadly categorize metalworking and forming processes into two main classes: bulk deformation and sheet metal forming. This classification of metal forming process can be further divided into subcategories, giving the different types of metal forming processes.
Bulk deformation: rolling, forging, extrusion, drawing
Bulk deformation reshapes the whole cross-section of the workpiece. It consists of roll forming – as we do here at SweBend, forging, extrusion, and wire and bar drawing.
Sheet forming: bending, roll bending, deep drawing, stretching
Sheet forming works thin, flat stock without changing its thickness much. It includes bending operations, stretching, deep drawing, and shearing.
Metal forming processes
| Process | Family | What it does | SweBend machine |
|---|---|---|---|
| Rolling | Bulk deformation | Passes metal between rolls to reduce thickness or curve plate and section | Plate rolls, section bending |
| Forging | Bulk deformation | Hammers or presses metal into a near-net shape | — |
| Extrusion | Bulk deformation | Forces metal through a die to a fixed cross-section | — |
| Drawing | Bulk deformation | Pulls metal through a die to reduce cross-section | — |
| Bending / roll bending | Sheet forming | Deforms sheet or plate around an axis to a set radius | Plate rolls, tailored forming |
| Deep drawing | Sheet forming | Draws sheet into a die cavity to form cups and shells | — |
| Stretch forming | Sheet forming | Stretches sheet over a form block | — |
| Shearing | Sheet forming | Cuts sheet by opposing blades (a forming-adjacent step) | — |
What is sheet metal forming?
Sheet metal forming shapes thin, flat metal into finished parts without adding or removing material. Now, let us come to the fundamentals of sheet metal forming processes and types of forming processes in sheet metal. Sheet metal forming processes can be extremely costly to undertake, especially if the sheets themselves are small in size and the designs to be formed are highly detailed. Therefore, one of the main sheet metal design considerations you need to think about is the type of metal used. Harder metals like carbonized steel might be stronger and more resilient. On the other hand, forming aluminum sheet metal is much easier due to aluminum’s characteristic properties. The many types of forming process in sheet metal include bending, flanging, hemming, seaming, drawing, and curling.
Different sheet metal forming techniques have different applications. Bending produces bends in the U or V shapes, used mostly for bending pipes and electrical components. Deep drawing is a type of reverse extrusion whereby the depth of the formation exceeds its diameter, such as cylinders and closed ducts. Another type of sheet metal forming is expansion which results in a mesh-like configuration used in fences, grates, and filters. Hydroforming is used mostly for strengthening and forming aluminum sheet metal in a single-step process. The products of such a sheet metal forming process include hydraulic systems and refrigeration frames.
How to form sheet metal
It all comes down to the required sheet metal production and sheet metal design fundamentals. To ensure that you get just the right outcome according to the desired sheet metal forming application, they need to be considered. If the sheet metal design fundamentals are not kept in mind at the design stage, manufacturers like yourself will have a hard time fixing those errors. Therefore, a quick tip would be to always keep in mind the sheet metal design considerations before procuring sheet metal to save yourself time and effort at the bending and forming stage and optimize your production. Sheet metal production is as much science as it is a craft and should be treated as such.
What materials are best for metal forming?
Ductile metals form best – low-carbon steel, stainless steel, aluminium, copper, and brass all deform without cracking. Formability depends on ductility, thickness, and grain direction. High-strength steels form too, but need higher roll power and a larger bend radius to control springback and avoid surface defects.
Metalworking has conventionally been applied to metals like silver, gold, brass, copper, and bronze. With the advent of more modern methods, aluminum, lead, and iron have increased in usage in recent times. Iron, when mixed in varying compositions with carbon, forms steel. Steel itself is of many types, depending on the carbon content, which in turn affects its strength and bendability. It can then be formed into tubes, sections, pipes, sheets, and many other shapes through extrusion, forging, casting, stamping, and roll forming.
Can metal form naturally?
Metal can deform under natural forces – thermal expansion, settling, or corrosion stress – but that movement is uncontrolled and usually unwanted. Industrial metal forming applies controlled force through rolls, dies, or presses to reach a precise, repeatable geometry that natural processes cannot deliver.
What are the 4 types of forging?
The four common forging types are open-die, closed-die (impression-die), seamless rolled ring, and upset forging. Each controls how metal flows under compressive force to build strength and near-net shape. Forging is one branch of metal forming, distinct from rolling and sheet-bending.
Why is metal forming important?
Metal forming turns raw stock into finished parts with fewer passes, less scrap, and repeatable precision. Because it reshapes metal rather than cutting it away, little material is wasted and grain flow is preserved for strength. For production, that means lower material cost, higher throughput, and consistent quality across batches.
The applications of metal forming span cargo ships, wind towers and turbines, rail and road, fluid tankers, and many more. Further advantages of metal forming processes include production of automobile parts, seaming and hemming edges for construction of bridges and pressure vessels, manufacturing of intricately detailed geometries for heat exchanger and power plant assemblies, and applications in the boatbuilding and aeronautics industries.
How SweBend machines form metal in production
SweBend builds the machines that turn these forming principles into production output. Our plate rolling machines bend flat plate into cylinders and cones with high bending force, so you reach the final shape in fewer passes and with less scrap. Our section bending machines roll beams, profiles, tubes, and angles on hydraulically adjustable guide rolls that support the material through the bend, reducing deformation and minimising flat ends. For non-standard geometries, tailored forming solutions adapt roll configurations and tooling to your exact material and job. Across all of them, the SEVEN CNC control stores programs and templates so operators repeat a job to the same tolerance every time.
Summary
In this article, we covered what metal forming is, how it differs from both bending and forging, the main types of forming processes, sheet metal forming, the materials that form best, and why metal forming matters for production.
If you want to know more about metal forming and sheet metal bending machines, please visit us at SweBend.com.
