Steel 1080 properties
Summary
Section titled “Summary”AISI 1080 steel is a high-carbon steel (0.75–0.88 % carbon) known for its excellent hardenability and high wear resistance. It is commonly supplied in annealed or normalized condition and, after proper heat treatment, achieves very high surface hardness. Typical applications include springs, cutting tools, cutlery, piano wires, and components requiring a combination of toughness and strength.
Chemical composition
Section titled “Chemical composition”| Element | Content (%) |
|---|---|
| Iron, Fe | 98.0 – 99.0 |
| Carbon, C | 0.75 – 0.88 |
| Manganese, Mn | 0.60 – 0.90 |
| Sulfur, S | 0.05 (max.) |
| Phosphorus, P | 0.04 (max.) |
Physical properties
Section titled “Physical properties”| Property | Metric | Imperial |
|---|---|---|
| Density | 7.7 – 8.03 g/cm³ | 0.278 – 0.290 lb/in³ |
Mechanical properties
Section titled “Mechanical properties”| Condition | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Hardness (HB) | Elastic Modulus (GPa) | Poisson’s Ratio |
|---|---|---|---|---|---|---|
| Annealed | 370 | 615 | 25 | 174 | 190 – 210 | 0.27 – 0.30 |
| Normalized | 420 | 710 | 20 | 201 | 190 – 210 | 0.27 – 0.30 |
| Oil quenched + tempered at 315 °C | 1275 | 1380 | 10 | 388 | 190 – 210 | 0.27 – 0.30 |
| Oil quenched + tempered at 540 °C | 827 | 965 | 17 | 293 | 190 – 210 | 0.27 – 0.30 |
Elastic modulus and Poisson’s ratio values are independent of heat treatment.
Thermal properties
Section titled “Thermal properties”| Property | Value | Condition / Temperature |
|---|---|---|
| Coefficient of thermal expansion | 14.7 × 10⁻⁶ /°C | 20–700 °C, annealed |
| Thermal conductivity | 48.1 W/m·K | at 100 °C |
| Specific heat | ~ 490 J/kg·K | room temperature (typical for carbon steels) |
| Melting point | ~ 1515 °C (2760 °F) | – |
Electrical and magnetic properties
Section titled “Electrical and magnetic properties”| Property | Typical value |
|---|---|
| Electrical resistivity | ~ 1.6 × 10⁻⁷ Ω·m (16 µΩ·cm) |
| Magnetic behavior | Ferromagnetic; magnetic saturation ≈ 2.1 T |
Heat treatments and fabrication
Section titled “Heat treatments and fabrication”- Annealing: heating to 790 °C, holding, and slow cooling in furnace. Provides minimum hardness and maximum machinability.
- Normalizing: heating to 870 °C followed by air cooling. Refines grain and improves uniformity.
- Quenching: austenitizing at 815 °C and rapid cooling in oil. Maximum hardness of about 65 HRC is achieved.
- Tempering: after quenching, between 150 °C and 650 °C depending on desired strength/toughness.
- Weldability: limited by high carbon content (CE ≈ 0.9). Preheating (200–300 °C) and post-weld treatment are required to avoid cracking.
Applications by industry
Section titled “Applications by industry”- Automotive: coil springs, leaf springs, suspension components.
- Tools: chisels, drill bits, saw blades, cutting dies.
- Cutlery and utensils: artisan knives, scissors, pocket knives.
- Musical instruments: piano strings (patented drawn wire).
- Agricultural machinery: plow shares, cultivator discs, wear parts.
- General: pins, retaining rings, surface-treated structural parts.
Comparison with similar materials
Section titled “Comparison with similar materials”| Grade | Carbon (%) | Strength in treated condition | Weldability | Typical application |
|---|---|---|---|---|
| AISI 1045 | 0.43 – 0.50 | Medium (≈ 620 MPa in Q&T) | Good (light preheat) | Shafts, gears, bolts |
| AISI 1080 | 0.75 – 0.88 | High (965–1380 MPa depending on temper) | Poor (requires controlled procedure) | Springs, tools, cutlery |
| AISI 1095 | 0.90 – 1.03 | Very high (up to 1420 MPa) | Very poor (high cracking risk) | Saw blades, high-strength springs |
Equivalent designations
Section titled “Equivalent designations”- AMS: 5110, 5110B
- ASTM: A29 (1080), A510 (1080), A576 (1080), A682 (1080), A713 (1080), A830
- SAE: J1397 (1080), J403 (1080), J412 (1080)
- MIL: MIL-S-16974
- DIN / EN: 1.1274 (C80U), C80E2U (equivalent non-alloy)
- JIS: SK85 (former SK5)
- ISO: C80U
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the hardness of 1080 steel in annealed condition?
Section titled “What is the hardness of 1080 steel in annealed condition?”Annealed 1080 steel has a Brinell hardness of approximately 174 HB, which facilitates machining prior to heat treatment.
What tensile strength does 1080 steel achieve after quenching and low-temperature tempering?
Section titled “What tensile strength does 1080 steel achieve after quenching and low-temperature tempering?”After oil quenching and tempering at 315 °C, tensile strength is around 1380 MPa (200 ksi), with yield strength near 1275 MPa.
What is the typical thermal conductivity of this material?
Section titled “What is the typical thermal conductivity of this material?”The thermal conductivity of 1080 steel is 48.1 W/m·K at 100 °C, a characteristic value for high-carbon steels.
In what density range does AISI 1080 steel fall?
Section titled “In what density range does AISI 1080 steel fall?”Its density ranges between 7.7 and 8.03 g/cm³ (0.278–0.290 lb/in³), varying slightly depending on the manufacturing process.
What is its coefficient of thermal expansion?
Section titled “What is its coefficient of thermal expansion?”In annealed condition, the linear coefficient of thermal expansion is 14.7 × 10⁻⁶ /°C in the range of 20 to 700 °C.
Exactly how much carbon does this steel contain?
Section titled “Exactly how much carbon does this steel contain?”AISI 1080 specification requires a carbon content between 0.75% and 0.88%, with maximums of 0.05% sulfur and 0.04% phosphorus.
References
Section titled “References”- azom.com: https://www.azom.com/article.aspx?ArticleID=6570
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/engineering-materials-properties-d_1225.html
- steelnumber.com: https://www.steelnumber.com/en/equivalent_steel_iron_eu.php?zname_id=12123