Steel grades are grades used to classify various

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

s by their

composition Composition or Compositions may refer to: Arts and literature *Composition (dance), practice and teaching of choreography * Composition (language), in literature and rhetoric, producing a work in spoken tradition and written discourse, to include ...

and physical properties. Steel grades have been developed by a number of

standards organizations A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary function is developing, coordinating, promulgating, revising, amending, reissuing, interpr ...

Steel grades standards by country

* For alloys in general (including steel),

unified numbering system The Unified Numbering System for Metals and Alloys (UNS) is an alloy designation system widely accepted in North America. Each UNS number relates to a specific metal or alloy and defines its specific chemical composition, or in some cases a speci ...

(UNS) of

ASTM International ASTM International, formerly known as American Society for Testing and Materials, is a standards organization that develops and publishes voluntary consensus technical international standards for a wide range of materials, products, systems and s ...

and the

Society of Automotive Engineers SAE International is a global professional association and standards organization based in Warrendale, Pennsylvania, United States. Formerly the Society of Automotive Engineers, the organization adopted its current name in 2006 to reflect bot ...

(SAE). *American steel grades : AISI/

SAE steel grades The SAE steel grades system is a standard alloy numbering system (SAE J1086 – Numbering Metals and Alloys) for steel grades maintained by SAE International. In the 1930s and 1940s, the American Iron and Steel Institute (AISI) and SAE were both ...

standard *

British Standards British Standards (BS) are the standards produced by the BSI Group which is incorporated under a royal charter and which is formally designated as the national standards body (NSB) for the UK. The BSI Group produces British Standards under th ...

International Organization for Standardization The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. M ...

br>ISO/TS 4949:2016
* European standards – EN 10027 *Japanese steel grades :

Japanese Industrial Standards are the standardization, standards used for industrial activities in Japan, coordinated by the Japanese Industrial Standards Committee (JISC) and published by the Japanese Standards Association (JSA). The JISC is composed of many nationwide co ...

(JIS) standard and NK standard *Germany steel grades :

DIN DIN or Din or din may refer to: People and language * Din (name), people with the name * Dīn, an Arabic word with three general senses: judgment, custom, and religion from which the name originates * Dinka language (ISO 639 code: din), spoken ...

standard *China steel grades : GB standard *Czech steel grades : ČSN standard *Russia steel grades :

GOST GOST () refers to a set of international technical standards maintained by the Euro-Asian Council for Standardization, Metrology and Certification (EASC), a regional standards organization operating under the auspices of the Commonwealth of I ...

standard *Spain steel grades : UNE standard *France steel grades :

AFNOR Association Française de Normalisation (AFNOR, English: French Standardization Association) is a Paris-based standards organization and a member body for France at the International Organization for Standardization (ISO). The AFNOR Group develop ...

standard *Italy steel grades : UNI standard *Sweden steel grades :

SIS Sis or SIS may refer to: People *Michael Sis (born 1960), American Catholic bishop Places * Sis (ancient city), historical town in modern-day Turkey, served as the capital of the Armenian Kingdom of Cilicia. * Kozan, Adana, the current name ...

standard *Norway steel grades : DNV standard Note that an increasing number of national European standards (DIN, AFNOR, UNE, UNI, etc.) and UK standards are being withdrawn and replaced by European Standards (EN). This task is carried out by the Comité Européen de Normalisation (CEN) (European Committee for Standardization).

European standard steel grades

European standard steel grade names fall into two categories: # Steel specified by purpose of use and mechanical properties. # Steel specified by chemical composition. The inclusion of a letter 'G' before the code indicates the steel is specified in the form of a casting.

Category 1: Steel specified by purpose of use and mechanical properties

Basic grade designations for category 1 steels consist of a single letter (designating application) then a number signifying the mechanical property (often yield strength) dictated in the standard for that application designation. For some application designations another letter is included before the property value, this number is used to indicate any special requirements or conditions. These additional letters and values depend entirely on the application of the steel and are specified in the standard and far too numerous to mention here. The next set of 3 digits gives the steel's minimum yield strength. So S355 has a minimum yield strength of 355 MPa for the smallest thickness range covered by the relevant standard – i.e. EN10025. Below is a table indicating the most common application codes.

Additional symbols

In addition to the above category codes there are symbols that can be added to the grade code to identify any additional compositional requirements, delivery conditions, mechanical properties, &c. These values depend solely on the type/application code given in the first part of the code and are so numerous as to be impossible to indicate here. Additional symbols are separated from the main code by the plus sign (+). The most common additional symbols are the impact and temperature codes for structural steels, category 1 - Sxxx. Example : S355J2 Delivery condition codes are also relatively common, the most common being: Example : S355J2+N

Electrical steel

Electrical steel type of product letters (bold are most recent version 2016):

Standard per steel name

According to EN 10027-1

Category 2: Steel specified by chemical composition

In addition to the descriptive steel grade naming system indicated above, within EN 10027-2 is defined a system for creating unique steel grade numbers. While less descriptive and intuitive than the grand names they are easier to tabulate and use in data processing applications. The number is in the following format: x.yyzz(zz)
Where x is the material type (only 1 is specified so far), yy is the steel group number (specified in EN10027-2) and zz(zz) is a sequential number designated by the certifying body, the number in brackets being unused but reserved for later use. The steel groups are indicated below: The current certification body is the VDEh in Düsseldorf, Germany.

Comparisons

Below is a table comparing steel grades from different grading systems.

American Petroleum Institute (API) steel grades

The American Petroleum Institute has a standardized steel grading system for various properties of steel composites.

Color coding

In order to clearly distinguish the steel grade, tubing, casing and its coupling should be painted with color codes respectively. Color bands should be painted o
tubing and casing
body longer than 600mm to either end. The whole outer-body of the coupling needs to be painted color and then color codes. API 5B and 5CT provide various steel grades and color codes of each grade, with general information of casing and tubing.

References

Notes

Bibliography

External links

Steel classification according to EN 10027-2.Free searchable database "European steel and alloy grades"

Comparison of various steel standards
{{Webarchive, url=https://web.archive.org/web/20190427173039/http://www.hagener-feinstahl.de/werkstoffliste2007.php?lng=en , date=2019-04-27
Comparison of various tool steel standards

Steels