SAE Carbon and Alloy Steel Grades
Jul 15, 2011 at 9:26 pm in Glossary, S by admin
Carbon steels and alloy steels are designated by a four digit number, where the first digit indicates the main alloying element or elements, the second digit indicates the secondary alloying element or elements, and the last two digits indicate the amount of carbon, in hundredths of a percent by weight. For example SAE1040 denotes plain carbon steel with .40 percent carbon. SAE4140 denotes chromium-molybdenum steel containing .40 percent carbon and about 1.0 percent of the major alloy (molybdenum). Plain carbon steels can contain anywhere from .06 to 1.7 percent carbon. Steels having over 1 percent carbon require a five-digit number.
The AISI numerical system is basically the same as the SAE system except it adds a prefix designating the process used to make the steel. It should be noted that the AISI standard has been functionally dormant since 1995:
- B-Acid Bessemer, carbon steel
- C-Basic open-hearth carbon steel
- CB-Either acid Bessember or basic open-hearth carbon steel at the option of the manufacturer
- D-Acid open-hearth carbon steel
- E-Electric furnace alloy steel
| 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 |
