AISI/SAE Steel Designations
Have you ever wondered how plain carbon and alloy grades are named? You can actually know how much carbon and what alloys are in the material by just knowing the designation.
Materials are designated by a four digit number, where
- the first digit indicates the main alloying element(s)
- the second digit indicates the secondary alloying element(s)
- the last two digits of these indicates the carbon content (hundredths of a percent)
(example, in Grade 1045 the 45 indicates a nominal carbon content of 0.45 wt% C)
Here is the naming system used to determine the steel designations: Enjoy.
GRADE TYPE OF STEEL & NOMINAL ALLOY CONTENT, %
Carbon Steels
10XX Plain carbon (Mn 1.00 max.)
11XX Resulfurized
12XX Resulfurized and rephosphorized
15XX Plain carbon (max Mn range; 1.00-1.65)
Manganese Steels
13XX Mn 1.75
Nickel Steels
23XX Ni 3.50
25XX Ni 5.00
Nickel-Chromium Steels
31XX Ni 1.25; Cr 0.65 and 0.80
32XX Ni 1.75; Cr 1.07
33XX Ni 3.50; Cr 1.50 and 1.57
34XX Ni 3.00; Cr 0.77
Molybdenum Steels
40XX Mo 0.20 and 0.25
44XX Mo 0.40 and 0.25
Chromium-Molybdenum Steels
41XX Cr 0.50, 0.80, and 0.95;
Mo 0.12, 0.20, 0.25, and 0.30
Nickel-Chromium-Molybdenum Steels
43XX Ni 1.82; Cr 0.50 and 0.80; Mo 0.25
43BVXX Ni 1.82; Cr 0.50; Mo 0.12 and 0.25; V 0.03 min
47XX Ni 1.05; Cr 0.45; Mo 0.20 and 0.35
81XX Ni 0.30; Cr 0.40; Mo 0.12
86XX Ni 0.55; Cr 0.50; Mo 0.20
87XX Ni 0.55; Cr 0.50; Mo 0.25
88XX Ni 0.55; Cr 0.50; Mo 0.35
93XX Ni 3.25; Cr 1.20; Mo 0.12
94XX Ni 0.45; Cr 0.40; Mo 0.12
97XX Ni 0.55; Cr 0.20; Mo 0.20
98XX Ni 1.00; Cr 0.80, Mo 0.25
Nickel-Molybdenum Steels
46XX Ni 0.85 and 1.82; Mo 0.20 and 0.25
48XX Ni 3.50; Mo 0.25
Chromium Steels
50XX Cr 0.27, 0.40, 0.50, and 0.65
51XX Cr 0.80, 0.87, 0.92, 0.95,1.00, and 1.05
Chromium (Bearing) Steels
50XXX Cr 0.50
51XXX Cr 1.02 C 1.00 min.
52XXX Cr 1.45
Chromium-Vanadium Steels
61XX Cr 0.60, 0.80, and 0.95; V 0.10 and 0.15 min
Tungsten-Chromium Steels
72XX W 1.75; Cr 0.75
Silicon-Manganese Steels
92XX Si 1.40 and 2.00; Mn 0.65, 0.82, and 0.85; Cr 0 and 0.65
High-Strength Low-Alloy Steels
9XX Various SAE grades
Boron Steels
XXBXX B denotes boron steel
Leaded Steels
XXLXX L denotes leaded steel