These are the lightest materials in our library, ranked by density. Engineering plastics are lightest, and among metals aluminum and titanium beat steel handily.
| Material | Density (g/cc) |
|---|---|
| UHMW | 0.93 |
| HDPE | 0.95 |
| ABS | 1.05 |
| Nylon 6/6 | 1.14 |
| Polycarbonate | 1.20 |
| PEEK | 1.32 |
| PVC | 1.40 |
| Acetal (Delrin) | 1.41 |
| PTFE | 2.20 |
| Aluminum | 2.70 |
| Titanium | 4.51 |
| Steel | 7.85 |
Steel is nearly three times as dense as aluminum and about eight times as dense as the lightest plastics, which is why weight-critical designs reach for aluminum, titanium, or polymers.
FAQ
Why not just always use the lightest material? Because density alone doesn’t determine whether a part can carry a given load. A thin-walled aluminum or titanium part often ends up lighter overall than an ultralight plastic part sized to match the same stiffness or strength, since polymers typically need a much larger cross-section to match a metal’s load capacity.
See the Material Density Chart and the Density Calculator.