Standard PN EN 10027-2 steel designation systems, part II

Standard PN-EN 10027-2:2015-07: Steel designation systems - Part 2: Number system - principles and structure

The PN-EN 10027-2 standard is an integral part of the European steel classification system and specifies the principles for assigning numerical designations to steel grades . It complements PN-EN 10027-1 , which addresses the letter designation system. The main goal of the standard is to ensure unambiguous identification of steel through a unique numbering system that eliminates the risk of duplication and interpretation errors.

Standard PN-EN 10027-2 – ranges

The standard describes how to code steel in a numerical format, which includes:

  • Division of steel into groups according to properties and purpose.
  • Rules for assigning unique numbers within individual material groups.
  • Steel number structure, their format and the order of the digits used.
  • Registration requirements and procedures for entering new numbers.

The numerical system covered by the standard applies to all types of steel used in Europe and includes:

PN-EN 10027-2 standard – steel number structure

Each number consists of five characters in the format:
1.XX XX, Where:

  • First digit ("1") – means that the material is steel.
  • Two consecutive digits ("XX") – define a group of steels according to their properties and applications (e.g. structural steels, stainless steel, tools).
  • The last two digits ("XX") – constitute a unique consecutive number of a given species within a group.

Steel numbering scheme:

Each steel group is assigned unique numerical ranges, which can be found in the tables in the standard.

Examples of numbers according to PN-EN 10027-2:

Rules for assigning and changing numbers in the PN-EN 10027-2 standard

1. Uniqueness of numbers

  • Steel numbers assigned according to the standard cannot be reused for other species.
  • Number changes are only permitted in exceptional circumstances and must follow specific procedures.

2 Registration and control of numbers

  • European Registration Office is responsible for supervising and recording steel numbers.
  • Applying for a new number requires checking whether the previous numbers in a given group have been fully used (e.g. all designations from 1.xx99 must be used before further designations are awarded, e.g. 1.xx9901).

3 Numbering of alloys other than steel

  • It is possible to assign numbers for materials other than steel (e.g. cast iron, non-ferrous metals).
  • Other numerical designations are used for these groups in accordance with the relevant standards.

The PN-EN 10027-2 standard is the most important document in the classification of steel, which:

  • Provides clear labeling steel grades, eliminating the possibility of repeating numbers.
  • Organizes numbering into logical groups, which facilitates the identification and use of materials.
  • It is a standard used in the steel, construction, automotive and materials engineering industries..

The standard, in combination with PN-EN 10027-1, provides a complete classification system, including both letter and numerical designations.

Classification of steel by numbering – Standard PN-EN 10027-2 

1.00XX – 1.07XX Non-alloy steels
1.08XX – 1.09XX Alloy steels        1.10XX –1.19XX Special unalloyed steels
  • 1.00XX – Basic steels
  • 1.01XX – Quality steels (general structural steels with Rm < 500 MPa)
  • 1.02XX – Other structural steels (not intended for heat treatment, with Rm < 500 MPa)
  • 1.03XX – Steels with an average carbon content of < 0,12% or Rm < 400 MPa
  • 1.04XX – Steels with an average carbon content of 0,12% ≤ C < 0,25% or 400 MPa ≤ Rm < 500 MPa
  • 1.05XX – Steels with an average carbon content of 0,25% ≤ C < 0,55% or 500 MPa ≤ Rm < 700 MPa
  • 1.06XX – Steels with an average carbon content of ≥ 0,55% or Rm ≥ 700 MPa
  • 1.07XX – Steels with increased phosphorus (P) or sulfur (S) content
  • 1.08XX – Steels with special physical properties
  • 1.09XX – Steels for other applications
  • 1.10XX – Steels with special physical properties
  • 1.11XX – Structural, boiler and engineering steels with C < 0,5%
  • 1.12XX – Structural, boiler and engineering steels with C ≥ 0,5%
  • 1.13XX – Structural, boiler and engineering steels with special requirements
  • 1.14XX – No classification
  • 1.15XX – 1.18XX – Tool steels
  • 1.19XX – No classification
1.20XX – 1.29XX Alloy tool steels
1.30XX – 1.39XX Special alloy steels
  • 1.20XX – Chromium steels (Cr)
  • 1.21XX – Cr-Si, Cr-Mn, Cr-Mn-Si steels
  • 1.22XX – Cr-V, Cr-V-Si, Cr-V-Mn, Cr-V-Mn-Si steels
  • 1.23XX – Cr-Mo, Cr-Mo-V, Mo-V steels
  • 1.24XX – Tungsten steels (W), Cr-W
  • 1.25XX – WV, Cr-WV steels
  • 1.26XX – Tungsten steels (excluding groups 24, 25 and 27)
  • 1.27XX – Steels with nickel (Ni)
  • 1.28XX – Other tool steels
  • 1.29XX – No classification
  • 1.30XX – No classification
  • 1.31XX – No classification
  • 1.32XX – High-speed steels with cobalt (Co)
  • 1.33XX – Cobalt (Co)-free high-speed steels
  • 1.34XX Abrasion-resistant steel, e.g. 1.3401
  • 1.35XX Bearing steels np 1.3505
  • 1.36XX – Materials with special magnetic properties without cobalt Co
  • 1.37XX – Materials with special magnetic properties with cobalt Co
  • 1.38XX – Materials with special physical properties without nickel Ni
  • 1.39XX – Materials with special physical properties with nickel Ni
1.4XXX – Stainless and heat-resistant steels
1.5XXX – Structural, boiler and engineering steels
  • 1.40XX Stainless steels with Ni < 2,5% without Mo, Nb and Ti, e.g 1.4034
  • 1.41XX Stainless steels with Ni < 2,5% and Mo, but without Nb and Ti, e.g 1.4122
  • 1.42XX – No classification
  • 1.43XX – Stainless steels with Ni ≥ 2,5% without Mo, Nb and Ti e.g. 1.4305
  • 1.44XX – Stainless steels with Ni ≥ 2,5% and Mo, but without Nb and Ti e.g. 1.4404
  • 1.45XX – Stainless steels with special additives
  • 1.46XX – Chemically and high-temperature resistant Ni alloys
  • 1.47XX – Heat-resistant steels with Ni < 2,5% e.g. 1.4718
  • 1.48XX Heat-resistant steels with Ni ≥ 2,5% e.g. 1.4828
  • 1.49XX – Materials with increased temperature properties
  • 1.50XX – Manganese-silicon-copper steels (Mn-Si-Cu)
  • 1.51XX – Manganese-silicon and manganese-chromium steels (Mn-Si, Mn-Cr)
  • 1.52XX – Manganese-copper, manganese-vanadium, silicon-vanadium steels (Mn-Cu, Mn-V, Si-V, Mn-Si-V)
  • 1.53XX – Manganese-titanium and silicon-titanium steels (Mn-Ti, Si-Ti)
  • 1.54XX – Molybdenum, niobium, titanium, vanadium and tungsten steels (Mo, Nb, Ti, V, W)
  • 1.55XX – Boron and manganese-boron steels with Mn < 1,65% (B, Mn-B)
  • 1.56XX – Nickel steels (Ni)
  • 1.57XX – Chrome-nickel steels with Cr < 1,0%
  • 1.58XX – Chrome-nickel steels with 1,0% ≤ Cr < 1,5%
  • 1.59XX – Chrome-nickel steels with 1,5% ≤ Cr < 2%
1.6XXX – Structural, boiler and engineering steels
1.7XXX – Structural, boiler and engineering steels
  • 1.60XX – Chrome-nickel steels with 2% ≤ Cr < 3%
  • 1.61XX – No classification
  • 1.62XX – Nickel-silicon, nickel-manganese and nickel-copper steels (Ni-Si, Ni-Mn, Ni-Cu)
  • 1.63XX – Nickel-molybdenum steels and their combinations with manganese, copper and vanadium (Ni-Mo, Ni-Mo-Mn, Ni-Mo-Cu, Ni-Mo-V, Ni-Mn-V)
  • 1.64XX – No classification
  • 1.65XX – Chrome-nickel-molybdenum steels with Mo < 0,4% + Ni < 0,2%
  • 1.66XX – Chrome-nickel-molybdenum steels with Mo < 0,4% + 2,0% ≤ Ni < 3,5%
  • 1.67XX – Chrome-nickel-molybdenum steels with Mo < 0,4% + 3,5% ≤ Ni < 5% or Mo ≥ 0,4% e.g. 1.6773
  • 1.68XX – Chrome-nickel-vanadium, chrome-nickel-tungsten, chrome-nickel-vanadium-tungsten steels (Cr-Ni-V, Cr-Ni-W, Cr-Ni-VW)
  • 1.69XX – Chromium-nickel steels (except groups 57 to 68)
  • 1.70XX – Chrome and chrome-boron steels (Cr, Cr-B)
  • 1.71XX – Chromium-silicon, chromium-manganese, chromium-manganese-boron and chromium-silicon-manganese steels (Cr-Si, Cr-Mn, Cr-Mn-B, Cr-Si-Mn)
  • 1.72XX – Chrome-molybdenum steels with Mo < 0,35% and chrome-molybdenum-boron steels (Cr-Mo, Cr-Mo-B)
  • 1.73XX – Chromium-molybdenum steels with Mo ≥ 0,35% (Cr-Mo)
  • 1.74XX – No classification
  • 1.75XX – Chrome-vanadium steels with Cr < 2,0% (Cr-V)
  • 1.76XX – Chrome-vanadium steels with Cr ≥ 2,0% (Cr-V)
  • 1.77XX – Chrome-molybdenum-vanadium steels (Cr-Mo-V)
  • 1.78XX – No classification
  • 1.79XX – Chrome-manganese-molybdenum and chrome-manganese-molybdenum-vanadium steels (Cr-Mn-Mo, Cr-Mn-Mo-V)
1.7XXX – Structural, boiler and engineering steels
1.8XXX – Structural, boiler and engineering steels
  • 1.70XX – Chrome and chrome-boron steels (Cr, Cr-B)
  • 1.71XX – Chromium-silicon, chromium-manganese, chromium-manganese-boron and chromium-silicon-manganese steels (Cr-Si, Cr-Mn, Cr-Mn-B, Cr-Si-Mn)
  • 1.72XX – Chrome-molybdenum steels with Mo < 0,35% and chrome-molybdenum-boron steels (Cr-Mo, Cr-Mo-B)
  • 1.73XX – Chromium-molybdenum steels with Mo ≥ 0,35% (Cr-Mo)
  • 1.74XX – No classification
  • 1.75XX – Chrome-vanadium steels with Cr < 2,0% (Cr-V)
  • 1.76XX – Chrome-vanadium steels with Cr ≥ 2,0% (Cr-V)
  • 1.77XX – Chrome-molybdenum-vanadium steels (Cr-Mo-V)
  • 1.78XX – No classification
  • 1.79XX – Chrome-manganese-molybdenum and chrome-manganese-molybdenum-vanadium steels (Cr-Mn-Mo, Cr-Mn-Mo-V)
  • 1.80XX – Chromium-silicon-molybdenum steels and their variants with manganese and vanadium (Cr-Si-Mo, Cr-Si-Mn-Mo, Cr-Si-Mo-V, Cr-Si-Mn-Mo-V)
  • 1.81XX – Chrome-silicon-vanadium, chrome-manganese-vanadium, chrome-silicon-manganese-vanadium steels (Cr-Si-V, Cr-Mn-V, Cr-Si-Mn-V)
  • 1.82XX – Chrome-molybdenum-tungsten steels and their variants with vanadium (Cr-Mo-W, Cr-Mo-WV)
  • 1.83XX – No classification
  • 1.84XX – Chrome-silicon-titanium, chrome-manganese-titanium, chrome-silicon-manganese-titanium steels (Cr-Si-Ti, Cr-Mn-Ti, Cr-Si-Mn-Ti)
  • 1.85XX Nitriding steels (Nitriding steels) e.g. 1.8519
  • 1.86XX – No classification
  • 1.87XX – Steels that do not require heat treatment by the user
  • 1.88XX – High-strength weldable steels that do not require heat treatment by the user
  • 1.89XX – High-strength weldable steels that do not require heat treatment by the user
1.9XXX – Unalloyed quality steels
2.XXXX – 9.XXXX other alloys, special alloys and metals   
  • 1.90XX – Basic steels
  • 1.91XX – Quality steels (general structural steels with Rm < 500 MPa)
  • 1.92XX – Other structural steels (not intended for heat treatment, with Rm < 500 MPa)
  • 1.93XX – Steels with an average carbon content of < 0,12% or Rm < 400 MPa
  • 1.94XX – Steels with an average carbon content of 0,12% ≤ C < 0,25% or 400 MPa ≤ Rm < 500 MPa
  • 1.95XX – Steels with an average carbon content of 0,25% ≤ C < 0,55% or 500 MPa ≤ Rm < 700 MPa
  • 1.96XX – Steels with an average carbon content of ≥ 0,55% or Rm ≥ 700 MPa
  • 1.97XX – Steels with increased phosphorus (P) or sulfur (S) content
  • 2.XXXX Nickel alloys (NP. Inconel, monel, Hastelloy, Incoloy).
  • 3.XXXX Cobalt alloys (e.g. Stellite, cobalt-chromium alloy).
  • 4.XXXX Titanium alloys (e.g. Ti-6Al-4V, Grade 2).
  • 5.XXXX Magnesium alloys (e.g. AZ31, Electron).
  • 6.XXXX Aluminum alloys (e.g. AlCu4Mg1 – 2024, AlMgSi – 6061).
  • 7.XXXX Copper alloys (e.g. CuSn8, CuZn40Pb2).
  • 8.XXXX Tin-lead alloys (e.g. SnPb solder, babbitt alloy).
  • 9.XXXX Other metals and special alloys (e.g. zirconium, tantalum, tungsten heavy alloys).

The PN-EN 10027-2 standard ensures the unambiguous identification of materials in technical documentation and facilitates their classification in international trade. Thanks to unified designations, also used in EN standards, easy compatibility with German standards is possible.

Werkstoff numbering system for alloys and metals not classified in PN-EN 10027-2

The Werkstoffnummer system (Werkstoff numbering) is a numerical classification of metallic materials developed in Germany and widely used in Europe. These designations are not directly covered by the PN-EN 10027-2 standard , which applies only to steel ( 1.XXXX – 1.97XX ), but also cover other metals and their alloys, such as nickel , cobalt, titanium , magnesium, aluminum , copper, tin, and lead.

European EN standards , including the numerical designations for the various groups of metals, are modelled on the German Werkstoffnummer system , which was developed by the Deutsches Institut für Normung (DIN) and is used in the metallurgical industry and in international technical documentation.

Division of Werkstoff numbering according to material groups

The Werkstoff numbering for alloys and non-alloy metals that are not classified in PN-EN 10027-2 covers the following ranges:

2.XXXX – Nickel alloys

Nickel alloys are characterized by high resistance to corrosion and oxidation under extreme thermal and chemical conditions. They are widely used in the aerospace, chemical, energy, and marine industries.

Examples:

  • Inconel® (e.g. Inconel® 718 Inconel® 625, Inconel® 600) – resistance to high temperatures and corrosion in oxidizing atmospheres.
  • monel® (e.g. Monel 400, Monel K-500) – high resistance to corrosion in acidic and alkaline environments, used in the marine industry.
  • Hastelloy® (e.g. Hastelloy C-276, Hastelloy X) – resistant to aggressive chemical media and high temperatures.

3.XXXX – Cobalt alloys

Cobalt alloys are characterized by exceptional wear resistance, high hardness , and stability under extreme conditions. They are primarily used in cutting tools, medical implants, and aircraft engines.

Examples:

  • Stellite (e.g. Stellite 6, Stellite 21) – stop cobalt, chrome i tungsten, used in wear-resistant coatings.
  • Cobalt-chromium alloys (e.g. CoCrMo, CoCrW) – used in medical implants (endoprostheses, stents) and cutting tools.
  • Elgiloy – a cobalt alloy used in the medical industry and high-strength springs.

4.XXXX – Titanium alloys

Titanium alloys are characterized by excellent strength-to-weight ratio, corrosion resistance , and biocompatibility. They are used in the aerospace, medical, and automotive industries.

Examples:

  • Ti-6Al-4V (Grade 5) – the most commonly used titanium alloy, used in the aerospace industry and medical implants.
  • Titanium Grade 2 - clean titanium with high corrosion resistance, used in chemistry and aviation.
  • Beta-titanium (Ti-β) – a high-elastic alloy used in the sports and automotive industries.

5.XXXX – Magnesium alloys

Magnesium alloys are characterized by extremely low density and are used where weight reduction is crucial, e.g. in aviation, automotive and electronics.

Examples:

  • AZ31 – magnesium alloy with aluminum material and zinc, used in aircraft and automotive structures.
  • Elektron (e.g. Elektron 21, Elektron WE43) – an alloy with high heat resistance, used in the space industry.
  • ZM21 – alloy resistant to corrosion, used in biomedical engineering.

6.XXXX – Aluminum alloys

Aluminum alloys are characterized by good thermal and electrical conductivity, corrosion resistance , and low density. They are widely used in the aviation, automotive, construction, and electronics industries.

Examples:

  • AlCu4Mg1 (A2024) – a high-strength aluminum alloy used in aviation.
  • AlMgSi (A6061) – a structural alloy used in construction and automotive.
  • AlZnMgCu (A7075) – a very durable alloy used in motor sports and aviation.

7.XXXX – Copper alloys

Copper alloys have high electrical and thermal conductivity and good corrosion resistance . They are widely used in electronics, the chemical industry, and construction.

Examples:

  • CuSn8 – tin bronze used in plain bearings and tools.
  • CuZn40Pb2 – leaded brass used in hydraulic fittings.
  • CuNi10Fe1Mn – copper alloy with nickel, resistant to marine corrosion.

8.XXXX – Tin and lead alloys

Tin and lead alloys are mainly used in soldering, plain bearings and protective coatings.

Examples:

  • SnPb solder alloy (e.g. 63/37, 60/40) – used in electronics.
  • Babbitt alloy – bearing material with a low coefficient of friction.
  • SnSbCu – an alloy of tin with antimony and copper, used in bearing coatings.

9.XXXX – Other metals and special alloys

This category includes metals and their alloys with unique properties, often used in specialized applications such as the space industry, electronics or nuclear reactors.

Examples:

  • Zirconium (Zr702, Zr705) – used in nuclear energy.
  • Tantalum (Ta10W, Ta2.5W) – resistant to corrosion, used in medicine and aviation.
  • Tungsten heavy alloys (e.g. W-Ni-Fe, W-Ni-Cu) – used in radiation shields and ammunition.

Check other steel standards according to PN, PN-EN, DIN, GOST, OST, ASTM, AFNOR, AISI and others

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