January 17, 2026

Are All Mechanical Power Presses Eccentric? A Complete Guide to Press Structures

In metal stamping and forming industries, mechanical power presses are among the most widely used production machines. Many customers often ask:

👉 Are all mechanical presses eccentric type?

The answer is: No.
Eccentric presses are only one category. Mechanical presses include several different transmission structures, each suitable for specific forming processes and production requirements.

This article explains the main types of mechanical presses, their working principles, advantages, and application scenarios to help you make the right equipment selection.

What Is a Mechanical Power Press?

A mechanical press converts motor-driven rotary motion into linear reciprocating motion through a flywheel and mechanical transmission system, allowing metal sheets to be punched, blanked, bent, drawn, and formed.

Compared with hydraulic presses, mechanical presses offer:

✅ Higher production speed
✅ Better repeatability
✅ Higher efficiency for mass production
✅ Lower operating cost

They are widely used in automotive parts, home appliances, electronics, hardware, and industrial components.

Are All Mechanical Presses Eccentric Type?

No. While eccentric presses are common, modern mechanical presses are mainly classified into the following structural types:

Main Types of Mechanical Power Presses

1️⃣ Eccentric Press

Uses an eccentric wheel to drive the slide motion.

Features:

Simple structure
High speed
Low maintenance cost

Applications:
Punching, blanking, shallow drawing, light forming

2️⃣ Crankshaft Press ✅ (Mainstream Type)

Uses a crankshaft and connecting rod mechanism to transmit force, offering better rigidity and stable tonnage near bottom dead center.

Features:

High rigidity
Stable forming force
Suitable for precision dies
Excellent repeatability

Applications:
Progressive stamping, deep drawing, automotive parts, precision metal forming

👉 Fuxing Machinery crankshaft mechanical presses are widely used in automotive, appliance, and hardware industries and can be integrated with automated feeding systems and robotic arms for smart production lines.
🌐 Website: www.fuxingmachinery.com

3️⃣ Knuckle Joint Press

Delivers extremely high force near bottom dead center with slower slide speed, ideal for precision forming.

Features:

Maximum forming force at BDC
High dimensional accuracy
Extended die life

Applications:
Cold extrusion, embossing, precision forging, fine blanking

4️⃣ Screw Press

Uses a flywheel-driven screw mechanism to deliver large forming energy per stroke.

Features:

High impact force
Flexible stroke control
Suitable for heavy-duty forming

Applications:
Forging, heavy forming, structural metal parts

Mechanical Press Structure Comparison

Type	Force Stability	Precision	Speed	Typical Applications
Eccentric	Medium	Medium	High	Punching & blanking
Crankshaft	High	High	High	Progressive dies & automotive parts
Knuckle Joint	Very High at BDC	Very High	Medium	Precision forming
Screw Press	Very High	High	Low	Forging applications

How to Choose the Right Mechanical Press?

Key selection factors include:

✅ Forming process requirements
✅ Part accuracy and tolerances
✅ Die complexity
✅ Production speed and output targets
✅ Automation integration needs

General guidance:

High-speed punching → Eccentric press
Progressive dies & deep drawing → Crankshaft press
Precision forming & cold extrusion → Knuckle joint press
Heavy-duty forming & forging → Screw press

Conclusion

Not all mechanical presses are eccentric type. While eccentric presses remain popular for light stamping, crankshaft presses have become the mainstream choice for medium and heavy-duty industrial production, while knuckle and screw presses serve specialized forming applications.

Choosing the correct press structure significantly improves productivity, product quality, and die life.