Steel grades to classify various steels by their composition and physical properties 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 (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 specific mechanical or physi ...

(UNS) of

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

and the

Society of Automotive Engineers SAE International, formerly named the Society of Automotive Engineers, is a United States-based, globally active professional association and standards developing organization for engineering professionals in various industries. SAE Internatio ...

(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 the a ...

International Organization for Standardization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Ar ...

ISO/TS 4949:2003 *

European standards European Standards (abbreviated EN, from the German name ("European Norm")) are technical standards which have been ratified by one of the three European standards organizations: European Committee for Standardization (CEN), European Committee for ...

– EN 10027 *Japanese steel grades :

Japanese Industrial Standards are the 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 committees and p ...

(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 by ...

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

GOST GOST (russian: ГОСТ) 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 th ...

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 standard *Norway steel grades :

DNV DNV (formerly DNV GL) is an international accredited registrar and classification society headquartered in Høvik, Norway. The company currently has about 12,000 employees and 350 offices operating in more than 100 countries, and provides servi ...

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 The European Committee for Standardization (CEN, french: Comité Européen de Normalisation) is a public standards organization whose mission is to foster the economy of the European Single Market and the wider European continent in global tr ...

(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

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, offering detailed and overall information of casing and tubing, which help you clearly pick out the most suitable products for different well application.

References

Notes

Bibliography

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External links

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

Comparison of various steel standards

Comparison of various tool steel standards

Steels