Steel HP 9-4-20
HP 9-4-20 typically has Yield Strength (YS) of 200-205 KSI, but there are other properties that have desirable values such as through-hardening, Charpy Impact Toughness of 84ft-lbs and elongation values of 14 to 18%. The YS value can be driven up approaching 235ksi; however, the fracture toughness value falls off quickly.
Chemical Properties
| Element | min | max |
| Carbon | 0.17 | 0.23 |
| Manganese | 0.20 | 0.40 |
| Silicon | — | 0.20 |
| Phosphorus | — | 0.010 |
| Sulfur | — | 0.010 |
| Chromium | 0.65 | 0.85 |
| Nickel | 8.50 | 9.50 |
| Cobalt | 4.25 | 4.75 |
| Molybdenum | 0.90 | 1.10 |
| Vanadium | 0.06 | 0.12 |
| Copper | — | 0.35 |
Mechanical Properties Minimum Tensile
| Property | Value |
| Tensile Strength | 190 ksi |
| Yield Strength at 0.2% Offset | 180 ksi |
| Elongation in 4D | 12% |
| Reduction of Area | 45% |
Select AMS Number:
| AMS Number | Alloy | Type | UNS | Cross Ref. Spec | Misc./Shape | |
|---|---|---|---|---|---|---|
| AMS 6468 | HP 9-4-20 | Steel | K91461 | - | Wire |
 |
| AMS 6523 Plate | HP 9-4-20 | Steel | K91472 | - | Plate |
 |
| AMS 6523 Sheet | HP 9-4-20 | Steel | K91472 | - | Sheet |
 |
| AMS 6523 Strip | HP 9-4-20 | Steel | K91472 | - | Strip |
 |
| AMS 6525 Bar | HP 9-4-20 | Steel | K91472 | - | Bar |
 |
| AMS 6525 Forging | HP 9-4-20 | Steel | K91472 | - | Forging |
 |
| AMS 6525 Ring | HP 9-4-20 | Steel | K91472 | - | Ring |
 |
| AMS 6525 Tubing | HP 9-4-20 | Steel | K91472 | - | Tubing |
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