• Second moment of area moment of inertiaSecond area moment calculation and radius of gyration of common shapes about weak and strong axes
  • Cubic orientation of primary and shear stresses and principal stress cosine rotationCombine primary and shear stresses into equivalent and principal stresses & their cosines
  • Nucleus and electron shells of atomic elementFind, sort and reorganise the properties of nature's atomic elements with active periodic table
  • Formulas included in Engineering PrinciplesCalculate unknowns in principle engineering formulas: stress, moments, power, energy, capstans, fluids, etc.
  • Properties of a triangle with inscribed and circumscribed circlesCalculate the properties of triangles and triangular configurations including inscribed and circumscribed circles
Area Moment calculation1 Combined Stress calculation2 Elements database3 Engineering Principles calculation4 Trigonometry calculation5
Materials Carbon Steel SAE Steel Grading Plain Carbon Steels Special Carbon Steels Alloy Carbon Steels Stainless Steels Uses Utilisation

SAE AISI Steel Grade Numbering System

SAE (together with AISI) has devised a numerical reference system for steel and its alloys that can accommodate a complete range of materials but which is incomplete as not all the numbers have yet been allocated a specification⁽¹⁾

The basis for their numbering system is provided below:

Plain Carbon Steels 10XX C <1, Mn <1
Free-Cutting Carbon Steels 11XX C <1, S >0.05
Free-Cutting Carbon Steels 12XX C <1, S >0.05, P >0.04
Manganese Steels 13XX C <1, Mn >1.65
High Hardness Steels 15XX C <1, Mn 1<1.65
Nickel Steels 23XX Ni 3.5
Nickel Steels 25XX Ni 5
Nickel Chromium Steels 31XX Ni 1.25, Cr 0.65<0.8
Nickel Chromium Steels 32XX Ni 1.75, Cr 1.07
Nickel Chromium Steels 33XX Ni 3.5, Cr 1.5<1.57
Nickel Chromium Steels 34XX Ni 3, Cr 0.77
Molybdenum Steels 40XX Mo 0.2<0.25
Chromium Molybdenum Steels 41XX Cr 0.5<0.95, Mo 0.12<0.3
Nickel Chromium Molybdenum Steels 43XX Ni 1.82, Cr 0.5<0.8, Mo 0.25
Molybdenum Steels 44XX Mo 0.4<0.52
Nickel Molybdenum Steels 46XX Ni 0.85<1.82, Mo 0.2<0.25
Nickel Chromium Molybdenum Steels 47XX Ni 1.05, Cr 0.45, Mo 0.2<0.35
Nickel Molybdenum Steels 48XX Ni 3.5, Mo 0.25
Chromium Steels 50XX Cr 0.27<0.65
Chromium Steels 51XX Cr 0.8<1.05
Chromium Steels 50XXX Cr 0.5, C >1.0
Chromium Steels 51XXX Cr 1.02, C >1.0
Chromium Steels 52XXX Cr 1.45, C >1.0
Chromium Vanadium Steels 61XX Cr 0.6<0.95, V 0.1<0.15
Chromium Tungsten Steels 72XX Cr 0.75, W 1.75
Nickel Chromium Molybdenum Steels 81XX Ni 0.3, Cr 0.4, Mo 0.12
Nickel Chromium Molybdenum Steels 86XX Ni 0.55, Cr 0.5, Mo 0.2
Nickel Chromium Molybdenum Steels 87XX Ni 0.55, Cr 0.5, Mo 0.25
Nickel Chromium Molybdenum Steels 88XX Ni 0.55, Cr 0.5, Mo 0.35
Manganese Silicon Steels 92XX Cr <0.65, Mn 0.65<0.85, Si 1.4<2
Nickel Chromium Molybdenum Steels 93XX Ni 3.25, Cr 1.2, Mo 0.12
Nickel Chromium Molybdenum Steels 94XX Ni 0.45, Cr 0.4, Mo 0.12
Nickel Chromium Molybdenum Steels 97XX Ni 0.55, Cr 0.2, Mo 0.2
Nickel Chromium Molybdenum Steels 98XX Ni 1, Cr 0.8, Mo 0.25

The plain carbon steel Table is the most important for defining the physical properties of all untreated carbon steels, including special and alloy steels. The last two digits in any carbon steel will tell you its percentage carbon; i.e. 1040, 1340 and 4140 all have the same carbon content (0.36<0.44, 0.38<0.43 and 0.38<0.43 respectively) and therefore possess similar physical properties (strength, elongation and hardness) before heat treatment or work hardening. However:
1) One or more of the basic alloying elements (manganese, phosphorus and sulphur) are increased in special carbon steels to improve machinability or increase hardness; no other alloying elements are added.
2) One or more of the basic alloying elements (manganese, phosphorus and sulphur) are altered in alloy carbon steels and supplementary elements are added for corrosion resistance and to further improve physical properties through heat treatment and work hardening.

The grade designation is prefixed with a 'G' and suffixed with a '0' (zero) in the UNS format {e.g. 1010 ≡ G10100}.
If the SAE-AISI grade designation is ...
... not prefixed with a character the steel has been manufactured using an open hearth furnace
... prefixed with a 'B' the steel has been manufactured using a Bessemer converter
... prefixed with a 'C' the steel has been manufactured using a crucible furnace
... prefixed with a 'E' the steel has been manufactured using an electric furnace
... suffixed with an 'F' the steel is of the free-cutting type
... suffixed with an 'H' the steel is manufactured to 'hardenability' limits
If the following character is inserted in the middle of the SAE-AISI grade designation ...
... 'B'; the chemical composition includes boron for improved hardness penetration (greater depth)
... 'L'; the chemical composition includes lead for improved machinability


  1. CalQlata has generated a predictive calculator for carbon and alloy steels

Further Reading

You will find further reading on this subject, incl. heat treatment, in our carbon steels web page

      Go to our store
CalQlata™ Copyright ©2011-2016 CalQlata info@calqlata.com Site Map Terms of website use Our Store