What Are Forgings? Key Advantages of Forged Parts

Forgings are metal parts shaped by pressing or hammering solid metal, usually hot, between dies. They are used wherever a part must carry high or repeated loads without failing: in vehicles, rail equipment, fire-fighting gear, climbing hardware and machinery.

This article explains what a forging is, how it differs from a casting or a machined part, and when forging is the right choice.

What is a forging?

A forging is a metal part formed by compressive force. A heated billet is placed in a die and pressed into shape. The metal never melts: it flows in the solid state, like very stiff clay.

That is the key difference from the other two common ways of making metal parts:

	Casting	Machining from bar	Forging
How it is made	Molten metal poured into a mold	Material cut away from solid stock	Solid metal pressed into shape in dies
Internal structure	Risk of porosity and shrinkage	Same as the bar stock	Dense, porosity closed
Grain flow	Random	Cut through by machining	Follows the shape of the part
Material use	Good	Poor: much of the bar becomes chips	Good, especially with near-net-shape dies
Best for	Complex shapes, low loads	Prototypes, low volumes	Load-bearing parts in volume

Main forging processes

• Hot forging: the metal is formed above its recrystallization temperature, which refines the grain structure for strength and toughness.
• Cold forging: forming at or near room temperature, for good dimensional accuracy and surface finish on smaller parts.
• Precision (near-net-shape) die forging: the forging comes out close to its final shape, so less machining is needed.
• Isothermal forging: die and workpiece are held at the same temperature, which gives a more uniform grain structure and suits high-strength aluminum alloys.

After forging, parts are usually heat treated and then CNC machined on their functional surfaces.

Key advantages of forged parts

1. Strength and fatigue resistance

Forging closes internal voids and makes the grain flow follow the outline of the part, so the strongest direction of the material runs along the load path. That is why connecting rods, wheel hubs and climbing carabiners are forged.

2. Reliability from part to part

A cast part can hide porosity that only shows up as a leak or a crack in service. A forging starts from solid, inspected material and is formed under controlled temperature and pressure, so its properties are consistent from one part to the next.

3. Less material and less machining

Near-net-shape forging puts the metal where the part needs it. At Aviaforge, near-net forming raises material utilization by about 30%. In one project, forged compressor wheel blanks used about 40% less material than machining the same wheel from bar stock (read the case study).

4. Good machinability

Dense, uniform forgings machine cleanly, which helps hold tight tolerances on bearing seats, threads and sealing faces.

5. Lighter designs

Because forged material is stronger and more uniform, a forged part can often be made thinner and lighter than a cast one. One Aviaforge client’s forged aluminum fire hose couplings came out about 18% lighter than the cast parts they replaced (read the case study).

When should you choose forging?

Forging is the right choice when a part:

• carries high, repeated or impact loads
• must not leak or crack, such as pressure parts and safety equipment
• is needed in volumes where die costs pay back, typically thousands of pieces
• would waste a lot of material if machined from bar

For one-off prototypes or very complex hollow shapes, machining or casting can be more economical.

What Aviaforge forges

Aviaforge has been forging metal parts since 1988, mainly from aluminum alloys (6061, 6082, 6063, 7075, 5083, 2024 and 2A14) and carbon steel, plus brass and stainless steel for hose couplings and clamps. The plant has seven servo-electric screw press forging lines up to 1,600 tons, in-house heat treatment and CNC machining, and is ISO 9001:2015 certified.

See our manufacturing capabilities or send us your drawing.

Frequently asked questions

Is a forging stronger than a casting? Generally, yes. Forging closes porosity and aligns the grain flow with the part’s shape, which improves strength, toughness and fatigue life compared with a casting of the same alloy.

What is the difference between forging and machining? Machining cuts a part out of solid stock and cuts through the grain flow. Forging shapes the metal so the grain follows the part. Most forgings are machined afterwards, but only on their functional surfaces.

Which metals can be forged? Most metals can be forged. Aviaforge mainly forges aluminum alloys and carbon steel.