There is probably no industry people operate in that does not involve some sort of machinery or pieces of equipment made of metal. Metals are vital and they come in different shapes and forms – as important raw materials, incredibly useful infrastructures, decorative interior elements, and even as complex medical instruments like the scalpel.
Without the sophisticated metalworking processes we’ve developed, none of these applications would be possible today. Let’s look at what makes metal processing a fundamental part of the industrialized world.
We’ll discuss the 4 main techniques that are part of shaping metals into the building elements of industrial machinery, the exquisite decorative elements, and geometrically accurate shapes that you can find everywhere around you. In doing so, you’ll be a step closer to gaining valuable insight into the metalworking processes that can be useful next time you’re contracting a metal piece for your home.
What Is Metalworking?
Metalworking consists of processes and techniques that shape or reshape metal parts into separate parts, constructions, objects, and large-scale structures. Metalworking encompasses a wide range of works across multiple industrial sectors.
For the marine industry, metalworks include one type of metal processing, decorative ironworks another, and precision metal manufacturing completely different.
The wide umbrella of categories and techniques that the process includes prompts a few questions. What categories of metalworking are there? And which are some of the main metalworking techniques?
Let’s start with answering the first question.
The 5 Fundamental Metalworking Processes
Fabricating metal pieces usually involves incorporating either one or a combination of forming, casting, cutting, joining, and machining. These are the most general categories of the metalworking process.
Here’s what each of the processes involves.
1. Forming
As the name suggests, forming aims to shape metal parts and objects into desired structures, through mechanical deformation.
Forming is performed without adding or removing material, and the weight of the metal piece remains unchanged. Forming is possible thanks to the metals’ physical properties, specifically malleability and plasticity, which allow us to permanently deform the physical shape of the materials.
Forming can further be divided into several subprocesses such as:
2. Bending
During this process, the metal sheet is bent by placing it over a die block that punch-presses the material and shapes it to the die. Bending is used in applications that require accuracy and smooth surfaces.
3. Forging
The processes encompass elements from bending and rolling, although forging is the more artistic side of a metal bending process.
It can be done both manually (heating the material and hammering it into the desired shape) or semi-manually, through the use of high-pressure machinery that compresses the metal, allowing craftsmen to bend and shape it.
Forging itself can be further divided into several categories like cold forging, warm forging, and hot forging, where the temperature of the element during work varies.
Forging is one of the oldest and most influential metalworking processes in our industrial history. It has been at the forefront of our technological development ever since we first discovered we could work metals.
Today, forging finds various applications in the iron and steel industries, and it’s an important process in the making of decorative and functional interior and exterior wrought iron pieces.
4. Drawing
In the process of drawing, the metal sheet is fixed into a place over a cavity-shaped die and punched to form hollow shaped components. The punch presses down and draws it into the cavity. The metal sheet ends up deformed to the external shape of the die.
5. Roll Forming
During roll forming, the metal is passed through consecutive sets of rollers while pairs of rollers continuously form and bend the sheets into the required, cross-sectional shape.
It’s a gradual process that takes time to form the metal into the exact shape.
Roll forming is used to manufacture elements with long lengths or for large production runs.
6. Casting
The casting process involves the creation of a mold (made of stone, plaster, or sand) with a certain shape in which molten metal is then poured. As the metal cools down and turns solid it takes the shape of the mold it has been poured into.
Metal casting, much like forging, is an ancient metalworking process we’ve been applying since 4000 BCE. Today it’s a vital process that serves heavy industries like the automotive and marine but is also used for making tools, jewelry, and sculptures.
7. Cutting
Metal cutting is also a pretty straightforward term used to describe the process where larger pieces of metal are separated by a cutting tool into smaller pieces.
Depending on the cutting tool, metal cutting can be subdivided into saw cutting, shearing, waterjet cutting, and laser cutting.
Saw cutting refers to the mostly manual technique of using a type of saw to cut through the metal.
Shearing relies on the force of a punch to cut at a specific point. It usually uses two tools (upper and lower) placed between the metal sheet which are then either punched or dyed into the sheet and cut.
Waterjet cutting uses the energy of high-speed, high-pressured, and high-density water that is projected into a small nozzle. The water is so pressurized that it reaches a speed approximately three times the speed of sound, which ends up forming a water jet with destructive force.
It’s a process used for metals that are sensitive to extreme temperatures and temperature changes.
Laser cutting uses lasers to cut metals. It works by directing a high-power laser, through optics and CNC (computer numerical control) to the material.
8. Machining
Metal machining involves techniques that shape raw metal pieces into finished products. Machining utilizes cutting processes (like CNC machines for laser cutting) but also includes processes like turning, drilling, milling, and extrusion.
During milling, an operator bores perforations into the metal.
Drilling on the other hand cuts holes into the sheet or piece with the use of circular bits.
Turning describes the operation, where a metal piece is placed into a spinning platform, and a technician makes radial cuts with different tools as the metal spins.
And finally, extrusion is the process in which a ram forces billets (solid metal bars with square or circle cross-sections) through a die, so cylindrical parts, such as pipes or electrical wires can be formed.
9. Joining
Metal joining is an important part of the metalworking processes because many of the final metal products are too large or complicated to be fabricated as a single piece. This results in the need for several metal pieces to be joined together to form the required metal component or machine.
Joining can be performed by two prominent processes- mechanical and liquid-solid-state. Mechanical joining includes additional elements like screws, nuts, and bolts, and liquid-solid-state joining concerns processes like adhesive bonding, brazing, soldering, and welding.
The Bottom Line
Metal fabrication might not be such a prevalent part of the common knowledge but we believe it’s an important topic that more people need to have a basic understanding of.
Understanding how metal pieces are created will give you valuable insight into a trade that has been the backbone of the industrial revolution and modern society.
It will also help you gain practical knowledge that will help navigate better your work with metalworks contractors, like Cacciola Iron Works.
Anthony Cacciola’s team of ironworks craftsmen has been helping homeowners in the New York and New Jersey areas make the best choice for their custom-made wrought iron gates and fences, doors, and railings.
Are you interested in how we apply our metalworking knowledge to practice? Get in touch today.
