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4340
4340 Product Guide
Applications | Specifications | Mechanical and Chemical Data | Tolerances
Overview
4340 steel has high strength, toughness, wear resistance, and fatigue strength. It can be machined in all states other than hardened and it is easily welded. Additionally, 4340 can be cold worked easily in the annealed state. This material is typically used in military aircraft, automotive systems, hydraulic parts, machine tools, and a steel crankshafts.
Common Trade Names
UNS G43400, AISI 4340, Alloy Steel
Other Resources
Weight Calculator | Mill Test Reports
Products
4340 Rectangle Bar | 4340 Round Bar | 4340 Sheet/Plate
Applications
- Aerospace
- Automotive
- Tooling
Specifications
AMS |
|---|
| 6415 |
| Physical Properties 4340 | |||
| Annealed | Normalized | ||
|---|---|---|---|
| Density | 0.284 lb/in3 | 0.284 lb/in3 | |
| Ultimate Tensile Strength | 108 ksi | 185.9 ksi | |
| Yield Tensile Strength | 68.2 ksi | 125 ksi | |
| Shear Strength | 63 ksi | 110 ksi | |
| Shear Modulus | 10.7 ksi | 11.3 ksi | |
| Hardness Rockwell | Brinell | B95 | 217 | B100 | 363 | |
| Elongation at Break Percentage | 22% | 12.2% | |
| Modulus of Elasticity | 27,800 ksi | 29,000 ksi psi | |
| Reduction of Area Percentage | 50% | 36.3% | |
| Poisson's Ratio | 0.29 | 0.29 | |
| Machinability Percentage | 50% | 50% | |
| Melting Point | 2,580-2,650 °F | 2,580-2,650 °F | |
| Specific Heat | 1.14 x 10^-1 BTU/lb-°F | 1.14 x 10^-1 BTU/lb-°F | |
| Thermal Conductivity | 309 BTU-in/hr-ft^2-°F | 309 BTU-in/hr-ft^2-°F | |
|
Chemistry Information
|
|
Element |
Percentage |
| C | 0.37 - 0.43 |
| Cr | 0.8 |
| Fe | 96 |
| Mn | 0.7 |
| Ni | 1.83 |
| P | 0.035 max |
| S | 0.04 max |
| Si | 0.23 |
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