What is Forging?

Forging is one of the oldest manufacturing processes for shaping metal. As there’s a range of techniques out there to treat metal, you may be confused as to what forging actually is. We’re here to help! In this blog, we go through all the ins and outs of forging, including the forging meaning, its types, the process, and its advantages. 

At Salamander Fabrications, we have a range of high-quality sheet metal fabrication services. With years of experience, we offer end-to-end, full service projects so our expert team takes care of every single stage. 

If you want to know more about the services we offer, feel free to get in touch with our sales team today at 01484 843599. We’d love to hear from you!

The Definition of Forging

Forging is essentially the use of compressive forces to shape metal- most of the time, the metal is heated (but not always!) and shaped using a hammer or die. The fact it’s still used today despite being one of the oldest metal shaping techniques shows its effectiveness as a process. 

Once the metal reaches the ideal temperature, great pressure is used to shape the metal into the desired shape. This then creates some very strong manufactured metals, and the process can be used on all kinds of metals. The reason for forging’s strengthening ability is because it alters a metal’s grain structure and refines it by breaking down any impurities. 

Basic and necessary forging equipment includes:

• Forge: A forge is the heating equipment that helps the metal reach the required temperature.
• Hammer: Hammers are used for harsh, high-impact force to strike and shape the metal.
• Pressers: Creates a controlled force instead of fast and harsh impacts like hammers do.
• Ring rollers: The metal is rolled between two rollers to produce rings, meaning welding is not needed.

Types of Forging 

All types of forging have the end goal of forging a metal into a desired shape, but how to achieve that is done in a variety of different ways. The type is based on the level of temperature applied, the level of pressure or even the tools used. Here are the most common types of forging:

Hot forging

With hot forging, the metal is heated above its recrystallisation temperature so then it can be reshaped easily. As it can be shaped more easily, manufacturers can reach their desired shape no matter how specific or complex.

Cold forging

Cold forging doesn’t involve intense high temperatures- instead, it is simply completed at room temperature. This sometimes requires softer metals so it can still be effectively reshaped without heat.

Closed-die forging

A die based on the desired final product is used and the metal is then reshaped until it fits the die’s impression. Closed-die forging therefore requires a higher force and can be done either hot or cold. 

Open-die forging 

Open-die forging uses no dies or a flat die. The metal isn’t enclosed like it is with closed-die forging, so it’s often used for larger or more simple parts of metal. It requires more manual skill with repeated pressure added and repositionings from the handler. 

Roll-forging

Metal is passed through two cylindrical, rotating dies. The metal is initially heated to be stretched out by the two rotating rollers, increasing the length of the metal. It continues to be passed through the rollers until the desired end-product is created.

The Forging Process

So, now that we’ve explained what forging is, you may be wondering what the process involves. Here are the most common and usual steps taken within the forging process:

Choosing the metal

This may be an obvious one, but choosing the metal is always the initial starting place. The choice may depend on the desired final product of the project, the type of forging used and the complexity of the shape. 

Heating

Obviously this step is for hot forging, but it is one of the most common types. The metal is heated to the desired temperature (usually above recrystallisation temperature). The chosen metal then softens and is likely to adopt a red, yellow or orange colour. 

Shaping

An anvil or die is then used to shape the heated (or room temperature) metal. The shape could be changed by hammering it, pressing it, or by using a die. It’s gradually shaped using a compressive force, either manually or with certain tools.

Cooling

If the metal has been subject to high heats, it may go through a cooling process to return to room temperature. However, this is optional and only used on heated metals. The metal could be left to cool down in the natural air and at room temperature. Or, the hot metal is immediately submerged in water to solidify its shape- this is called ‘quenching’. 

Finishing

Once the above steps are complete, the finishing touches are added to the metal! This could include sanding or filing the metal down to perfect the chosen shape, giving it a more refined appearance.

Advantages of Forging 

So, what are the advantages of using the forging process to reshape metal? Let’s take a look: 

Stronger metal parts

As mentioned, forging creates some very strong metal parts through its process. This is because it refines the metal, creating a smaller grain pattern and therefore closing any gaps within the metal. It also changes the grain flow, aligning it with the shape of the part. The pieces then become more durable as a result of its reshaping.

The stronger parts are certainly more long lasting as they’re less prone to wear and tear. It avoids surface cracking because of its refined grain structure, so you can rest assured that the forged part will be able to withstand any harsh conditions.

Cost effective

As the metal parts created are stronger, they ultimately become more reliable, meaning you don’t have to replace those metal parts as often. Production time is often faster than methods like casting. While the initial cost of the equipment can be quite high, high-volume production makes it worthwhile. 

Forging is such an effective process so the metal likely won’t need to go through any secondary processes, which would lead to more cost. Its reliability as a process ultimately makes it less costly due to less replacement of metal parts and once you’ve got the equipment, that’s basically it!

Flexible designs

Shapes can be customisable based on the shapes of the die and presses. Though it doesn’t help create intricate detail, it allows transformational changes to be made to the particular metal used. 

Changes to both grain flow and its shape show just how customisable it can be, and how it can be applied to a versatile range of metals.

What sectors is forging used in?

Forging is commonly used in sectors that need to have long-lasting and durable parts. These tend to be within the industrial sectors, where metal parts need to be fatigue resistant and endure harsh conditions. 

• Automotive: Forging is used to make gear systems, crankshafts and driving rods that can withstand harsh conditions.
• Aerospace and Aviation: Strong and fatigue resistant parts ensure aviation safety, and forging often makes engine shafts and landing gear.
• Building and Construction: Used for hardware tools and heavy machinery that can help aid construction.
• Agriculture: Commonly used for tractor parts, tiles and agricultural tools.

At Salamander Fabrication, we operate in a range of sectors, from transportation to construction. Our sheet metal fabrication offers flexibility and our expert team makes parts that are fit for purpose. 

Choose Salamander Fabrications for all your Metal Shaping Needs

While we don’t offer forging services, we offer a range of metal shaping services that may be more fitting for what you’re looking for. Customisable shapes can be cut using our laser cutting services, or you may be wanting to join separate pieces of metal together, in which case our expert welding services could be just what you’re looking for.

Have a question about an upcoming project or our services in general? Don’t hesitate to get in touch to find out more!

FAQs

1. Is forging stronger than casting?

Put simply, yes! Forging compresses the metal, creating a continuous grain flow. However, casting gives metals a random grain flow, making it more prone to cracks as it has less fatigue resistance. 

While casting pours molten metal into a mould, forging moulds the metal using compressive forces, which generally creates much stronger parts.

2. Is forging different from sheet metal fabrication?

Yes! Both deal with the shaping of metal, but with different methods to achieve the end goal. Sheet metal fabrication shapes thin metal sheets by a range of techniques such as welding, cutting, bending and so on. 

However, forging is used on thicker metals and forms strengthened metals. Forging is great for shaping durable, large parts whereas sheet metal fabrication creates parts that are directly fit for purpose.