1018 Steel properties
1018 is a low-carbon mild steel, one of the most common general-purpose steels. It is easy to machine, weld, and form, takes case hardening well, and is widely used for shafts, pins, and machine parts. Values below are for the cold-drawn condition.
Mechanical properties
| Property | Value |
|---|---|
| Yield strength | 54 ksi (370 MPa) |
| Ultimate tensile strength | 64 ksi (440 MPa) |
| Elongation | 15% |
| Hardness | 126 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 | 51.9 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
1018 is a workhorse for shafts, pins, dowels, spacers, studs, and general machined parts. Its low carbon makes it easy to weld and form, and it case-hardens by carburizing to give a hard wearing surface over a tough core, which suits gears and wear components.
How it compares
Among carbon steels, 1018 sits at the soft, ductile, easily worked end. It is weaker than medium-carbon 1045 and far weaker than alloy steels like 4140, but it machines and welds more readily and costs less, which is why it is the default choice when high strength is not required.
FAQ
Is 1018 steel hardenable?
Not by through-hardening, because its carbon is too low. It is case-hardened instead, by carburizing to add carbon to the surface for a hard skin over a tough core.
Can 1018 be welded?
Yes, very readily. Its low carbon content gives excellent weldability with no special precautions for most work.
What is the difference between 1018 and A36?
1018 is a bar-stock steel with tighter composition, better for machining, while A36 is a structural steel for plates and shapes. Cold-drawn 1018 is also stronger than A36.