Numbering Example
- 10xx
- First digit indicates the general category, carbon steels, \(\;1\:\)
- Second digit indicates the presence of major element %, plain carbon, \(\;0\:\)
- Last two digit indicates percentage of carbon present in the steel, \(\;xx\;\)
- 10Lxx
- First digit indicates the general category, carbon steels, \(\;1\;\)
- Second digit indicates the presence of major element %, plain carbon, \(\;0\:\)
- Last two digit indicates percentage of carbon present in the steel, \(\;xx\:\)
- Letter designation indicates title of the material or specification, lead \(\;L\:\)
- 46xx
- First digit indicates the general category, nickel molybdenum steels, \(\;4\:\)
- Second digit indicates the presence of major element %, nickel, \(\;6\:\)
- Last two digit indicates percentage of carbon present in the steel, \(\;xx\:\)
Letter Designation
A - Aluminum, B - Brass, C - Copper Alloy, S - Steel, W - Wire, N - Nickel Alloy, L - Lead, M - Magnesium Alloy, M - Magnet or Magnetic, P - Plate Gold, P - Platinum Foil, P - Plating Cadmium, R - Rods Welding, R - Resistance Wire, S - Solder various, S - Steel Bar, S - Steel Alloy sheet and strip, S - Steel Corrosion Resisting, M - Manganese Alloy, S - Steel Castings, B - Bronze, C - Copper, N - Nickel
AISI/SAE Steel Numbering System | ||
|---|---|---|
| Numbering | General Category | Major Element % |
| 10XX | carbon steels | Plain carbon, Mn 1.00% max |
| 11XX | " | Resulfurized free machining |
| 12XX | " | Resulfurized / rephosphorized free machining |
| 15XX | " | Plain carbon, Mn 1.00-1.65% |
| 13XX | manganese steels | Mn 1.75% |
| 23XX | nickel steels | Ni 3.50% |
| 25XX | " | Ni 5.00% |
| 31XX | nickel chromium steels | 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% |
| 40XX | molybdenum steels | Mo 0.20-0.25% |
| 44XX | " | Mo 0.40-0.52% |
| 41XX | chromium molybdenum steels | Cr 0.50-0.95%, Mo 0.12-0.30% |
| 43XX | nickel chromium molybdenum steels | Ni 1.82%, Cr 0.50-0.80%, Mo 0.25% |
| 47XX | " | Ni 1.05%, Cr 0.45%, Mo 0.20-0.35% |
| 46XX | nickel molybdenum steels | Ni 0.85-1.82%, Mo 0.20-0.25% |
| 48XX | " | Ni 3.50%, Mo 0.25% |
| 50XX | chromium steels | Cr 0.27-0.65% |
| 51XX | " | Cr 0.80-1.05% |
| 50XXX | " | Cr 0.50%, C 1.00% min |
| 51XXX | " | Cr 1.02%, C 1.00% min |
| 52XXX | " | Cr 1.45%, C 1.00% min |
| 61XX | chromium vanadium steels | Cr 0.60-0.95%, V 0.10-0.15% |
| 72XX | tungsten chromium steels | W 1.75%, Cr 0.75% |
| 81XX | nickel chromium molybdenum steels | Ni .30%, Cr 0.40%, Mo 0.12% |
| 86XX | " | Ni .55%, Cr 0.50%, Mo 0.20% |
| 87XX | " | Ni .55%, Cr 0.50%, Mo 0.25% |
| 88XX | " | Ni .55%, Cr 0.50%, Mo 0.35% |
| 92XX | silicon manganese steels | Si 1.40-2.00%, Mn 0.65-0.85%, Cr 0-0.65% |
| 93XX | nickel chromium molybdenum steels | 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% |
