Different Steel Grades and Their Designation

In the current climate, characterized by economic disruptions from the COVID pandemic, logistics bottlenecks, increasing energy prices, and ongoing geopolitical conflicts, companies are compelled to reassess their procurement strategies for steel and other metals. However, changing suppliers is not a straightforward task.

The variance in steel grade designation systems across Europe and other regions can create confusion for those engaged in the buying or selling of steel.

This article aims to clarify the most commonly used steel grade classifications, eventually leading to a strong reference point: a Steel Grade Equivalency Table.

A General Explanation of Steel Grade Standards and Their Importance

The complexity of steel grades arises from the fact that different countries have established their own standardization systems, often leading to various names for steels with similar compositions and physical properties. Furthermore, some private producers and suppliers develop their own standards, compounding the confusion.

Defining Steel Grade

A steel grade serves as a classification mechanism for different steels based on their composition and physical characteristics. Steel grades exhibit diverse behaviors and serve distinct functions.

There are over 3,500 steel grades available today (75% of which are relatively new). These grades can be categorized into four primary groups:

• Carbon Steel: This is the most widely utilized steel, typically comprising mostly iron (Fe) with less than 1% carbon (C) along with trace amounts of other metals. Carbon enhances hardness, but excessive carbon can make the material brittle.
• Alloy Steel: Alloy steels are produced by adding elements like nickel (Ni), copper (Cu), chromium (Cr), or aluminum (Al) to change their properties.
• Stainless Steel: This type comprises 10-20% chromium (Cr), which forms a protective coating against corrosion, making it ideal for various constructions and customer-facing applications.
• Tool Steel: Designed for durability and high heat resistance, tool steels are used in cutting and drilling applications.

While these categories provide a basic overview, they do not offer the granularity required for specific purchasing needs, leading to the necessity for unique grade classifications.

This article outlines the five prevalent national standards to note when buying steel in Europe and beyond: EN, DIN, AFNOR, UNI, SAE. Each standard includes unique identifiers that indicate chemical and mechanical properties.

As an example, EN S235JR is the European standard for a non-alloy general construction steel. For sales in Germany, it's recommended to convert to DIN St37-2.

A unique anchor point is provided in our overview of automotive steel grades, which are essential for the automotive industry.

Understanding National Standards and Their Application

We will examine two specific steel grades across different standards for better understanding:

Detailed Breakdown of the EN Standards

The EN standard specifies product requirements and commonly uses letter-number combinations to denote properties like type and yield strength.

The Importance of DIN Standards

DIN standards provide a comprehensive view of the steel's chemical composition and other relevant attributes.

Understanding AFNOR, UNI, and SAE/AISI Designations

AFNOR, UNI, and SAE/AISI standards also utilize unique identifiers to illustrate the steel's chemical makeup and mechanical properties. Notably, they assist in global compatibility and standardization.

For more specifics, including information on abrasion resistant steel plate properties, please consult additional resources.

To gain deeper insights into ar steel properties, visit our dedicated sections.