FOUR DIGIT ALLOY NUMBERING SYSTEMS
WHAT THOSE NUMBERS MEAN WHEN
ORDERING STEEL
NOTE: Alloying elements are in weight
percent, XX denotes carbon content.
| 10XX | Basic plain carbon steel |
| 11XX | Plain carbon steel with high sulfur & low phosphorous (Resulferized) |
| 12XX | Plain carbon steel with high sulfur & high phosphorous |
| 13XX | 1.75 manganese |
| 23XX | 3.50 nickel (series deleted in 1959) |
| 25XX | 5.00 nickel (series deleted in 1959) |
| 31XX | 1.25 nickel & 0.60 chromium (series deleted in 1959) |
| 33XX | 3.50 nickel & 1.50 chromium (series deleted in 1959) |
| 40XX | 0.20 - 0.25 molybdenum |
| 41XX | 0.50 - 0.95 chromium & 0.12 - 0.30 molybdenum |
| 43XX | 1.83 nickel, 0.50 - 0.80 chromium & 0.25 molybdenum |
| 44XX | 0.53 molybdenum |
| 46XX | 0.85 or 1.83 nickel & 0.23 molybdenum |
| 47XX | 1.05 nickel, 0.45 chromium &0.20 - 0.35 molybdenum |
| 48XX | 3.5 nickel & 0.25 molybdenum |
| 50XX | 0.40 chromium |
| 51XX | 0.80 - 1.00 chromium |
| 61XX | 0.60 0r 0.95 chromium & 0.13 - 0.15 vanadium |
| 86XX | 0.55 nickel, 0.50 chromium & 0.20 molybdenum |
| 87XX | 0.55 nickel, 0.50 chromium & .25 molybdenum |
| 88XX | 0.55 nickel, 0.50 chromium & .35 molybdenum |
| 92XX | 2.00 silicon |
| 93XX | 3.25 nickel, 1.20 chromium & 0.12 molybdenum (series deleted in 1959) |
| 98XX | 1.00 nickel, 0.80 chromium & 0.25 molybdenum (series deleted in 1959) |
ALLOYING ELEMENTS
| Aluminum | Deoxidizes and restricts grain growth |
| Baron | Increases hardenability and strength |
| Carbon | Increases hardenability and strength |
| Chromium | Increases corrosion resistance, hardenability and wear resistance |
| Lead | Increases machinibility |
| Manganese | Increases hardenability and counteracts brittleness from sulfur |
| Molybdenum | Deepens hardening, raises creep strength and hot-hardness, enhances corrosion resistance and increases wear resistance |
| Nickel | Increases strength and toughness |
| Phosphorus | Increases strength, machinability, and corrosion resistance |
| Silicon | Deoxidizes, helps electrical and magnetic properties, improves hardness and oxidation resistance |
| Titanium | Forms carbides, reduces hardness in stainless steels |
| Tungsten | Increases wear resistance and hot hardness |
| Vanadium | Increases hardenability |
| TO BUY BY CHECK |