1045 Steel properties
1045 is a medium-carbon steel that is stronger and harder than mild steels like 1018, while still being weldable with care. It can be through-hardened by heat treatment, making it a popular choice for shafts, axles, bolts, and gears. Values are for the hot-rolled condition.
Mechanical properties
| Property | Value |
|---|---|
| Yield strength | 45 ksi (310 MPa) |
| Ultimate tensile strength | 82 ksi (565 MPa) |
| Elongation | 16% |
| Hardness | 163 HB (Brinell) |
| Modulus of elasticity | 29,000 ksi (200 GPa) |
Physical properties
| Property | Value |
|---|---|
| Density | 0.284 lb/in³ (7870 kg/m³) |
| Melting point | about 1480 to 1525 °C |
Thermal properties
| Property | Value |
|---|---|
| Thermal conductivity | 49.8 W/m·K |
| Thermal expansion | 11.5 µm/m·°C |
| Specific heat | 486 J/kg·K |
Values are typical for the grade and condition shown. Actual properties vary with temper, heat treatment, and product form, so use these for comparison and preliminary design and confirm against material certificates for final work.
Compare with other materials
See the Material Properties Comparison, Yield Strength, and Density charts.
Typical uses
1045 is used for shafts, axles, spindles, gears, bolts, studs, and machine parts that need more strength than mild steel. Because it has enough carbon to through-harden, it can be quenched and tempered to raise strength substantially for higher-duty parts.
How it compares
1045 bridges the gap between soft mild steels and tougher alloy steels. It is stronger and harder than 1018 but less weldable and less ductile, and it lacks the deep hardenability of alloy steels like 4140, which use added chromium and molybdenum.
FAQ
Can 1045 steel be hardened?
Yes. Its medium carbon content allows through-hardening by quenching and tempering, or flame and induction hardening for a hard surface.
Is 1045 steel weldable?
It can be welded, but its higher carbon means preheating and post-weld care are often needed to avoid cracking, unlike mild steel.
What is 1045 steel used for?
Shafts, axles, gears, bolts, and machine components needing moderate to high strength, especially where heat treatment will be applied.