AISI 4140 steel is a low alloy steel containing chromium, molybdenum, and manganese. It is widely used across numerous industries and is an excellent material choice due to its toughness, high fatigue strength, and abrasion and impact resistance. Not many grades can match the versatility and usefulness of 4140.
| Chemistry | Content(%) |
|---|---|
| Iron, Fe | 96.745 – 97.67 |
| Chromium, Cr | 0.8 – 1.1 |
| Manganese, Mn | 0.75 – 1.0 |
| Carbon, C | 0.48 – 0.53 |
| Silicon, Si | 0.15 – 0.30 |
| Molybdenum, Mo | 0.15 – 0.25 |
| Sulfur, S | ≤ 0.04 |
| Phosphorous, P | ≤ 0.035 |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile Strength | 731 MPa | 106000 psi |
| Yield Strength | 380 MPa | 55100 psi |
| Izod Impact | 24 J | 17.7 ft-lb |
| Bulk Modulus | 140 GPa | 20300 ksi |
| Shear Modulus | 80 GPa | 11600 ksi |
| Elastic Modulus | 190 – 210 GPa | 27557 – 30458 ksi |
| Poisson’s Ratio | 0.27 – 0.30 | 0.27 – 0.30 |
| Elongation at Break | 20.20% | 20.20% |
| Reduction of Area | 40% | 40% |
| Hardness, Brinell | 197 | 197 |
| Hardness, Knoop | 219 | 219 |
| Hardness, Rockwell B | 92 | 92 |
| Hardness, Rockwell C | 13 | 13 |
| Hardness, Vickers | 207 | 207 |
| Machinability | 55 | 55 |
AMS 6349 chromium-molybdenum alloy is a deep hardening steel used where strength and impact toughness are required.
It has high fatigue strength making it suitable for critical stressed applications at normal as well as elevated temperatures. For increased resistance to wear and abrasion, it may be nitrided. This grade is a quality product melted under the best of steel making practices for aircraft quality steels. It is vacuum degassed to meet the magnetic particle inspection standards of AMS 2301. The alloy is supplied in the normalised and cold finished, hot finished and normalised or normalised and cold finished condition. The density of this material is typically 7.85kg/dm³.
Intended for general use for parts with sections ½” or less in thickness at time of heat treatment which require a through-hardening steel capable of developing hardness as high as Rockwell “C” 50; also for fittings and forgings of greater hardness or variation in thickness at proportionately lower hardnesses. It is frequently used in applications in which 8640 (MIL-S-6049) is specified.
Commercial applications for this engineering material include:
| Chemistry | Content(%) |
|---|---|
| Iron, Fe | 96.745 – 97.67 |
| Chromium, Cr | 0.8 – 1.1 |
| Manganese, Mn | 0.75 – 1.0 |
| Carbon, C | 0.48 – 0.53 |
| Silicon, Si | 0.15 – 0.30 |
| Molybdenum, Mo | 0.15 – 0.25 |
| Sulfur, S | ≤ 0.04 |
| Phosphorous, P | ≤ 0.035 |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile Strength | 731 MPa | 106000 psi |
| Yield Strength | 380 MPa | 55100 psi |
| Izod Impact | 24 J | 17.7 ft-lb |
| Bulk Modulus | 140 GPa | 20300 ksi |
| Shear Modulus | 80 GPa | 11600 ksi |
| Elastic Modulus | 190 – 210 GPa | 27557 – 30458 ksi |
| Poisson’s Ratio | 0.27 – 0.30 | 0.27 – 0.30 |
| Elongation at Break | 20.20% | 20.20% |
| Reduction of Area | 40% | 40% |
| Hardness, Brinell | 197 | 197 |
| Hardness, Knoop | 219 | 219 |
| Hardness, Rockwell B | 92 | 92 |
| Hardness, Rockwell C | 13 | 13 |
| Hardness, Vickers | 207 | 207 |
| Machinability | 55 | 55 |
AMS 6349 chromium-molybdenum alloy is a deep hardening steel used where strength and impact toughness are required.
It has high fatigue strength making it suitable for critical stressed applications at normal as well as elevated temperatures. For increased resistance to wear and abrasion, it may be nitrided. This grade is a quality product melted under the best of steel making practices for aircraft quality steels. It is vacuum degassed to meet the magnetic particle inspection standards of AMS 2301. The alloy is supplied in the normalised and cold finished, hot finished and normalised or normalised and cold finished condition. The density of this material is typically 7.85kg/dm³.
Intended for general use for parts with sections ½” or less in thickness at time of heat treatment which require a through-hardening steel capable of developing hardness as high as Rockwell “C” 50; also for fittings and forgings of greater hardness or variation in thickness at proportionately lower hardnesses. It is frequently used in applications in which 8640 (MIL-S-6049) is specified.
Commercial applications for this engineering material include:
