Differences Between Ordinary Steel and Special Steel

Key Takeaways

• Ordinary steel is cost-effective, easy to process, and widely used for general structural and machine components.

• Special steel contains alloying elements that provide higher strength, heat resistance, and corrosion resistance for demanding applications.

• Choosing between ordinary and special steel depends on the required performance, operating environment, and heat treatment needs.

Overview

In metal machining, steel is one of the most important materials. It can be broadly divided into ordinary (carbon) steel and special (alloy) steel, each with unique properties and applications. This article explains the key differences and where each type is used.

Differences Between Ordinary Steel and Special Steel

Ordinary Steel

Ordinary steels are used as general purpose materials for a wide range of applications and are typically used without heat treatment. It contains chemical elements such as carbon (C), silicon (Si), manganese (Mn), phosphorus (P), and sulfur (S), with common examples being SS400 and other SS-grade steels.

Examples of Ordinary Steel:

• General structural rolled steel (SS grades)

• Weldable structural rolled steel (SM grades)

• Carbon and molybdenum steel plates for boilers and pressure vessels (SB grades)

• Cold-rolled steel sheets (SPC grades)

Ordinary steel is widely available, cost effective, and easy to work with, making it suitable for a broad range of uses such as general structural components and machine parts.

Special Steel

Special steel is widely used in components that require higher performance than ordinary steel or are used under severe conditions, but it requires heat treatment. It contains more alloying elements than ordinary steel. The addition of elements such as chromium (Cr), nickel (Ni), and molybdenum (Mo) gives it high strength, heat resistance, and corrosion resistance.

Examples of Special Steel:

• Carbon steel for machine structures (SC grades)

• Carbon tool steel (SK grades)

• Stainless steel (SUS grades)

• High speed tool steel (SKH grades)

• Heat resistant steel (SUH grades)

Special steel is used when higher performance is needed. It is particularly common in industries such as aerospace, automotive, tool manufacturing, and other high-temperature or corrosive environments.

Step Up Your Project with Yumoto Electric

Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of metals using milling, turning, and specialized metal processing. We have experience with over 200 materials including aluminum alloys, stainless steel, molybdenum, and titanium. 

If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.