Extrusion and forging are important metal forming processes used to shape materials by plastic deformation under compressive forces.

While extrusion produces long components with a uniform cross-section by forcing metal through a die, forging shapes metal by applying compressive loads to obtain strong, durable components. Understanding the differences between extrusion and forging helps in selecting the appropriate process based on shape, mechanical properties, and application requirements.

Extrusion Vs Forging: 15 Differences:

Below is a detailed, point-by-point comparison of Extrusion vs Forging, written in a clear, exam-ready format, including principle, process, characteristics, advantages, and applications.

1. Basic Definition

Aspect	Extrusion	Forging
Definition	A metal forming process in which material is forced to flow through a die to produce a uniform cross-section	A metal forming process in which metal is shaped by compressive forces using hammers or presses

2. Principle of Operation

Extrusion	Forging
Metal flows under compressive stress through a die opening	Metal is plastically deformed by compressive impact or squeezing forces
Material flows in the direction of extrusion	Material flows in multiple directions to fill the die cavity

3. Type of Forces

Aspect	Extrusion	Forging
Nature of force	Continuous compressive force	Intermittent or continuous compressive force
Stress state	Predominantly compressive and shear	Purely compressive

4. Temperature of Operation

Extrusion	Forging
Can be cold, warm, or hot extrusion	Mostly hot forging; also cold and warm forging
Hot extrusion reduces force requirement	Hot forging improves ductility

5. Shape and Geometry

Extrusion	Forging
Produces long components with uniform cross-section	Produces complex shapes with varying cross-sections
Length is much greater than cross-section	Suitable for discrete components

6. Grain Flow and Mechanical Properties

Aspect	Extrusion	Forging
Grain flow	Grains elongate along the extrusion direction	Grain flow follows the contour of the component
Strength	Moderate mechanical strength	Very high strength and fatigue resistance

7. Tooling and Dies

Extrusion	Forging
Uses extrusion dies with constant profile	Uses open-die or closed-die (impression) dies
Die wear is moderate	Die wear is high due to heavy impact loads

8. Material Utilization

Extrusion	Forging
High material utilization, minimal scrap	Some material loss as flash
No flash formation	Flash removal often required

9. Surface Finish and Accuracy

Extrusion	Forging
Excellent surface finish and close tolerances	Good finish but may require machining
Suitable for near-net shape production	Machining often needed for precision

10. Production Rate

Extrusion	Forging
Continuous and high production rate	High production rate for mass production
Ideal for long products	Ideal for high-strength components

11. Equipment Used

Extrusion	Forging
Hydraulic extrusion press	Forging hammer or forging press
Lower impact loads	High impact and noise (hammer forging)

12. Typical Materials

Extrusion	Forging
Aluminum, copper, magnesium, lead	Steel, aluminum, titanium, nickel alloys

13. Applications

Extrusion	Forging
Pipes, tubes, channels, window frames, heat sinks	Crankshafts, connecting rods, gears, bolts, spanners

14. Advantages

Extrusion

Produces complex cross-sections
High surface finish
Minimal material waste
Uniform properties along length

Forging

Superior mechanical properties
High structural integrity
Excellent fatigue resistance
Suitable for critical components

15. Limitations

Extrusion	Forging
Limited to constant cross-section	High tooling and equipment cost
High force required for hard materials	Flash and die wear

Summary Table

Feature	Extrusion	Forging
Product shape	Constant cross-section	Varying cross-section
Strength	Moderate	Very high
Material waste	Very low	Moderate
Grain flow	Linear	Contour-aligned
Typical products	Long sections	Discrete parts

Conclusion

Extrusion is preferred for long products with uniform cross-section, while forging is chosen for high-strength components where superior mechanical properties are required.