Steel Alloy Designation

Steel Alloy Designation System
AISI-SAE Designation Number	Type and Description
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, 0.80
32xx	Ni 1.75; Cr 1.07
33xx	Ni 3.50; Cr 1.50, 1.57
34xx	Ni 3.00; Cr 0.77
Molybdenum steels
40xx	Mo 0.20, 0.25
44xx	Mo 0.40, 0.52
Chromium-molybdenum steels
41xx	Cr 0.50, 0.80, 0.95; Mo 0.12, 0.20, 0.25, 0.30
Nickel-chromium-molybdenum steels
43xx	Ni 1.82; Cr 0.50, 0.80; Mo 0.25
43BVxx	Ni 1.82; Cr 0.50; Mo 0.12, 0.25; V 0.03 min.
47xx	Ni 1.05; Cr 0.45; Mo 0.20, 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 1.00; Cr 0.20; Mo 0.20
98xx	Ni 1.00; Cr 0.80; Mo 0.25
Nickel-molybdenum steels
46xx	Ni 0.85, 1.82; Mo 0.20, 0.25
48xx	Ni 3.50; Mo 0.25
Chromium steels
50xx	Cr 0.27, 0.40, 0.50, 0.65
51xx	Cr 0.80, 0.87, 0.92, 0.95, 1.00, 1.05
50xxx	Cr 0.50; C 1.00 min.
51xxx	Cr 1.02; C 1.00 min.
52xxx	Cr 1.45; C 1.00 min.
Chromium-vanadium steels
61xx	Cr 0.60, 0.80, 0.95; V 0.10, 0.15
Tungsten-chromium steels
72xx	W 1.75; Cr 0.75
Silicon-manganese steels
92xx	Si 1.40, 2.00; Mn 0.65, 0.82, 0.85; Cr 0.00, 0.65
High-strength low-alloy steels
9xx	Various SAE grades
Boron steels
xxBxx	B denotes boron steels
Leaded steels
xxLxx	L denotes leaded steels