Managers in productions processes must know and understand the system by which raw materials they use are graded and the codes that indicate those grades. This is important from the front office all the way down to the shop floor. Engineering and project managers need to select the correct material not only for their project, but that is feasible to use within the configuration of their existing equipment capabilities. Purchasing needs to understand what they looking for in the marketplace and what, if any substitutions are allowed. First line supervisors must be aware of any special tooling requirements coming their way on pending job tickets. The following article contains information important to all levels of management for manufacturing operations that use various steels in their process.



Grading steel is an activity performed by various standardizing organizations. These standards organizations operate independently of the users who rely on these standards.

Two organizations that perform these functions are:

*Society of Automotive Engineers - SAE International (SAE)

*International Organization for Standardization (ISO)

Grading is necessary because of the different chemical compositions that go into manufacturing steel. With the various types of steel, there are a myriad of chemical combinations. Grading is also necessary because of the quality requirements for the different types of steel. With grading, a purchaser can look at what makes up a certain type of steel. He can use this grading system to choose the type of steel to meet his need.

With SAE grading, a system of letters and numbers designates grades of steel. Most of SAE's specifications are in line with those of the American Iron and Steel Institute. This system identifies carbon and alloy steels of various specifications. Alloy steels are steels that are a combination of metals.

The SAE system identifies different types of chemical composition. Their numbering system symbolizes certain standards they have set. These standards refer to the machining, heat treating, and carburizing performance of steel. Carburizing is the addition of carbon to the surface of low-carbon steels. An SAE grading has a letter as a prefix, and then a number after the prefix.

The letter prefixes are:

B - Acid Bessemer carbon steel

C - Basic open-hearth carbon steel

E - Electric furnace steel

Basin open-hearth alloy steel does not have a prefix.

Three examples of the longer list of numbers associated with the prefixes are:

*(10XX series) Basic open-hearth and acid Bessemer carbon steel grades, non-sulfurized and non-phosphorized

*(1300 series) Manganese 1.60 to 1.90%

*(93XX series) Nickel 3.0%-chromium-molybdenum

With the ISO grading system, standards are in place as applies to the various types of steel. There are standards for applications applied to steel as well. Theirs is a numbering system, too and they constantly update their system to include new products and processes.

Here's an example of an ISO specification:

* ISO 8504-1:2000 Preparation of steel substrates before application of paints and related products- Surface preparation methods-Part 1: General principles

The reading of this numbered document prepared by the ISO would give their standards for the above process in working with steel. There are manuals available that lay this system out in detail. ISO states that they seek to set quality standards for business, governments and society in general.

Grading systems for steels classify steel according to type. For example, there is stainless steel, galvanized steel and carbon steel. Stainless steel is further broken down into various grades of stainless steel.

ASTM International (ASTM) develops and publishes voluntary technical standards for industry. Their original name was the American Society for Testing and Materials. They have standards for structural steel used in the construction industry.

Steel standards, set by various independent organizations, ensure quality steel hits the market. These standards ensure that manufacturers know exactly what the composition is of the steel they buy. These standards also help them decide what type of steel is necessary for their project. They can choose a type of steel for a certain harsh environment based on the grading provided.

Grading systems for steels benefit producers, manufacturers, buyers, and users of steel. It is an instrumental part of any production operation that makes products using metals as a raw material.