SAE steel grades

Iron alloy phases

Ferrite (α-iron, δ-iron)
Austenite (γ-iron)
Pearlite (88% ferrite, 12% cementite)
Martensite
Bainite
Ledeburite (ferrite-cementite eutectic, 4.3% carbon)
Cementite (iron carbide, Fe3C)

Steel classes

Crucible steel
Carbon steel (≤2.1% carbon; low alloy)

Spring steel (low or no alloy)

Alloy steel (contains non-carbon elements)

Maraging steel (contains nickel)
Stainless steel (contains ≥10.5% chromium)
Weathering steel
Tool steel (alloy steel for tools)
Other iron-based materials

Cast iron (>2.1% carbon)

Ductile iron
Gray iron
Malleable iron
White iron

Wrought iron (contains slag)

The Society of Automotive Engineers (SAE) designates SAE steel grades. These are four digit numbers which represent chemical composition standards for steel specifications. The American Iron and Steel Institute (AISI) originally started a very similar system. Over time they used the same numbers to refer to the same alloy, but the AISI system used a letter prefix to denote the steelmaking process. The prefix "C" denoted open-hearth furnace, electric arc furnace or basic oxygen furnace, while "E" denotes electric arc furnace steel.

Prior to 1995 the AISI was also involved, and the standard was designated the AISI/SAE steel grades. The AISI stopped being involved because it never wrote any of the specifications.

Contents

  • 1 Carbon and alloy steel
  • 2 Stainless steel
  • 3 High-strength low-alloy steel
  • 4 See also
  • 5 References
    • 5.1 Notes
    • 5.2 Bibliography

Carbon and alloy steel

Carbon steels and alloy steels 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), and the last two digits indicate the amount of carbon, in hundredths of a percent by weight. For example, a 1060 steel is a plain-carbon steel containing 0.60 wt% C.

An "H" suffix can be added to any designation to denote hardenability is a major requirement. The chemical requirements are loosened but hardness values defined for various distances on a Jominy test.

Major classifications of steel
SAE designation Type
1xxx Carbon steels
2xxx Nickel steels
3xxx Nickel-chromium steels
4xxx Molybdenum steels
5xxx Chromium steels
6xxx Chromium-vanadium steels
7xxx Tungsten steels
8xxx Nickel-chromium-vanadium steels
9xxx Silicon-manganese steels
Carbon and alloy steel grades
SAE designation Type
Carbon steels
10xx Plain carbon (Mn 1.00% max)
11xx Resulfurized
12xx Resulfurized and rephosphorized
15xx Plain carbon (Mn 1.00% to 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% or 0.80%
32xx Ni 1.25%, Cr 1.07%
33xx Ni 3.50%, Cr 1.50% or 1.57%
34xx Ni 3.00%, Cr 0.77%
Molybdenum steels
40xx Mo 0.20% or 0.25% or 0.25% Mo & 0.042 S
44xx Mo 0.40% or 0.52%
Chromium-molybdenum (Chromoly) steels
41xx Cr 0.50% or 0.80% or 0.95%, Mo 0.12% or 0.20% or 0.25% or 0.30%
Nickel-chromium-molybdenum steels
43xx Ni 1.82%, Cr 0.50% to 0.80%, Mo 0.25%
43BVxx Ni 1.82%, Cr 0.50%, Mo 0.12% or 0.35%, V 0.03% min
47xx Ni 1.05%, Cr 0.45%, Mo 0.20% or 0.35%
81xx Ni 0.30%, Cr 0.40%, Mo 0.12%
81Bxx Ni 0.30%, Cr 0.45%, 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% or 1.82%, Mo 0.20% or 0.25%
48xx Ni 3.50%, Mo 0.25%
Chromium steels
50xx Cr 0.27% or 0.40% or 0.50% or 0.65%
50xxx Cr 0.50%, C 1.00% min
50Bxx Cr 0.28% or 0.50%
51xx Cr 0.80% or 0.87% or 0.92% or 1.00% or 1.05%
51xxx Cr 1.02%, C 1.00% min
51Bxx Cr 0.80%
52xxx Cr 1.45%, C 1.00% min
Chromium-vanadium steels
61xx Cr 0.60% or 0.80% or 0.95%, V 0.10% or 0.15% min
Tungsten-chromium steels
72xx W 1.75%, Cr 0.75%
Silicon-manganese steels
92xx Si 1.40% or 2.00%, Mn 0.65% or 0.82% or 0.85%, Cr 0.00% or 0.65%
High-strength low-alloy steels
9xx Various SAE grades
xxBxx Boron steels
xxLxx Leaded steels

Stainless steel

Stainless steel designations
SAE designation UNS designation  % Cr  % Ni  % C  % Mn  % Si  % P  % S  % N Other
Austenitic
201 S20100 16–18 3.5–5.5 0.15 5.5–7.5 0.75 0.06 0.03 0.25 -
202 S20200 17–19 4–6 0.15 7.5–10.0 0.75 0.06 0.03 0.25 -
205 S20500 16.5–18 1–1.75 0.12–0.25 14–15.5 0.75 0.06 0.03 0.32–0.40 -
254 S31254 20 18 0.02 max - - - - 0.20 6 Mo; 0.75 Cu; "Super austenitic"; All values nominal
301 S30100 16–18 6–8 0.15 2 0.75 0.045 0.03 - -
302 S30200 17–19 8–10 0.15 2 0.75 0.045 0.03 0.1 -
302B S30215 17–19 8–10 0.15 2 2.0–3.0 0.045 0.03 - -
303 S30300 17–19 8–10 0.15 2 1 0.2 0.15 min - Mo 0.60 (optional)
303Se S30323 17–19 8–10 0.15 2 1 0.2 0.06 - 0.15 Se min
304 S30400 18–20 8–10.50 0.08 2 0.75 0.045 0.03 0.1 -
304L S30403 18–20 8–12 0.03 2 0.75 0.045 0.03 0.1 -
304Cu S30430 17–19 8–10 0.08 2 0.75 0.045 0.03 - 3–4 Cu
304N S30451 18–20 8–10.50 0.08 2 0.75 0.045 0.03 0.10–0.16 -
305 S30500 17–19 10.50–13 0.12 2 0.75 0.045 0.03 - -
308 S30800 19–21 10–12 0.08 2 1 0.045 0.03 - -
309 S30900 22–24 12–15 0.2 2 1 0.045 0.03 - -
309S S30908 22–24 12–15 0.08 2 1 0.045 0.03 - -
310 S31000 24–26 19–22 0.25 2 1.5 0.045 0.03 - -
310S S31008 24–26 19–22 0.08 2 1.5 0.045 0.03 - -
314 S31400 23–26 19–22 0.25 2 1.5–3.0 0.045 0.03 - -
316 S31600 16–18 10–14 0.08 2 0.75 0.045 0.03 0.10 2.0–3.0 Mo
316L S31603 16–18 10–14 0.03 2 0.75 0.045 0.03 0.10 2.0–3.0 Mo
316F S31620 16–18 10–14 0.08 2 1 0.2 0.10 min - 1.75–2.50 Mo
316N S31651 16–18 10–14 0.08 2 0.75 0.045 0.03 0.10–0.16 2.0–3.0 Mo
317 S31700 18–20 11–15 0.08 2 0.75 0.045 0.03 0.10 max 3.0–4.0 Mo
317L S31703 18–20 11–15 0.03 2 0.75 0.045 0.03 0.10 max 3.0–4.0 Mo
321 S32100 17–19 9–12 0.08 2 0.75 0.045 0.03 0.10 max Ti 5(C+N) min, 0.70 max
329 S32900 23–28 2.5–5 0.08 2 0.75 0.04 0.03 - 1–2 Mo
330 N08330 17–20 34–37 0.08 2 0.75–1.50 0.04 0.03 - -
347 S34700 17–19 9–13 0.08 2 0.75 0.045 0.030 - Nb + Ta, 10 x C min, 1 max
348 S34800 17–19 9–13 0.08 2 0.75 0.045 0.030 - Nb + Ta, 10 x C min, 1 max, but 0.10 Ta max; 0.20 Ca
384 S38400 15–17 17–19 0.08 2 1 0.045 0.03 - -
Ferritic
405 S40500 11.5–14.5 - 0.08 1 1 0.04 0.03 - 0.1–0.3 Al, 0.60 max
409 S40900 10.5–11.75 0.05 0.08 1 1 0.045 0.03 - Ti 6 x C, but 0.75 max
429 S42900 14–16 0.75 0.12 1 1 0.04 0.03 - -
430 S43000 16–18 0.75 0.12 1 1 0.04 0.03 - -
430F S43020 16–18 - 0.12 1.25 1 0.06 0.15 min - 0.60 Mo (optional)
430FSe S43023 16–18 - 0.12 1.25 1 0.06 0.06 - 0.15 Se min
434 S43400 16–18 - 0.12 1 1 0.04 0.03 - 0.75–1.25 Mo
436 S43600 16–18 - 0.12 1 1 0.04 0.03 - 0.75–1.25 Mo; Nb+Ta 5 x C min, 0.70 max
442 S44200 18–23 - 0.2 1 1 0.04 0.03 - -
446 S44600 23–27 0.25 0.2 1.5 1 0.04 0.03 - -
Martensitic
403 S40300 11.5–13.0 0.60 0.15 1 0.5 0.04 0.03 - -
410 S41000 11.5–13.5 0.75 0.15 1 1 0.04 0.03 - -
414 S41400 11.5–13.5 1.25–2.50 0.15 1 1 0.04 0.03 - -
416 S41600 12–14 - 0.15 1.25 1 0.06 0.15 min - 0.060 Mo (optional)
416Se S41623 12–14 - 0.15 1.25 1 0.06 0.06 - 0.15 Se min
420 S42000 12–14 - 0.15 min 1 1 0.04 0.03 - -
420F S42020 12–14 - 0.15 min 1.25 1 0.06 0.15 min - 0.60 Mo max (optional)
422 S42200 11.0–12.5 0.50–1.0 0.20–0.25 0.5–1.0 0.5 0.025 0.025 - 0.90–1.25 Mo; 0.20–0.30 V; 0.90–1.25 W
431 S41623 15–17 1.25–2.50 0.2 1 1 0.04 0.03 - -
440A S44002 16–18 - 0.60–0.75 1 1 0.04 0.03 - 0.75 Mo
440B S44003 16–18 - 0.75–0.95 1 1 0.04 0.03 - 0.75 Mo
440C S44004 16–18 - 0.95–1.20 1 1 0.04 0.03 - 0.75 Mo
Heat resisting
501 S50100 4–6 - 0.10 min 1 1 0.04 0.03 - 0.40–0.65 Mo
502 S50200 4–6 - 0.1 1 1 0.04 0.03 - 0.40–0.65 Mo
Duplex
2205 S31803
S32205
22 5 0.03 max - - - - 0.15 3 Mo; All values nominal
Super duplex
2507 S32750 25 7 0.03 max - - - - 0.28 4 Mo; All values nominal