---
title: "PLA — density, melting point and properties"
description: "PLA has a density of 1,240 kg/m³ (1,210–1,300). Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/pla/
site: "At One Place"
---

# PLA

**Density of PLA: 1,240 kg/m³ (1,210–1,300)**

1.24 g/cm³ · 77.4 lb/ft³

Made from fermented plant sugar rather than oil, and stiffer and stronger in short-term tension than ABS, which surprises people who assume the eco material is the weaker one. Its weakness is heat: it starts to soften around 60 °C, so a PLA part left in a parked car in summer will droop. "Compostable" means industrially compostable at 58 °C with controlled humidity — in a garden heap or a landfill it lasts for years.

## Properties

- **Density:** 1,240 kg/m³ (1,210–1,300) — 1.24 g/cm³
- **Melting range:** 150–165 °C
- **Tensile strength:** 45–70 MPa
- **Young's modulus:** 3.5 GPa
- **Thermal conductivity:** 0.13 W/(m·K)
- **Thermal expansion:** 68 µm/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Desktop 3D printing filament
- Compostable food packaging and cutlery
- Disposable cups and lids
- Prototype and display parts

## How it compares

*Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.*

- air: 1.2 kg/m³
- expanded polystyrene foam: 20 kg/m³
- rigid polyurethane foam: 40 kg/m³
- Water — the float line: 1,000 kg/m³
- PLA: 1,240 kg/m³
- tungsten: 19,250 kg/m³
- gold: 19,300 kg/m³
- platinum: 21,450 kg/m³

*Water is 1,000 kg/m³. Anything below that floats.*

| Material | Density | Relative to water |
| --- | --- | --- |
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| PLA ← | 1,240 kg/m³ | 1.24× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

PLA contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

PLA is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of PLA?

1,240 kg/m³ (1,210–1,300), or 1.24 g/cm³.

### Does PLA float?

No. At 1,240 kg/m³ it is denser than water.

### Is PLA magnetic?

PLA is not a metal and has no ferromagnetic response.

## Related pages

- [Does PLA float?](https://atoneplace.net/does-it-float/pla/)
- [ABS](https://atoneplace.net/material/abs/)
- [Acrylic (PMMA)](https://atoneplace.net/material/acrylic/)
- [Polycarbonate](https://atoneplace.net/material/polycarbonate/)
- [Polypropylene](https://atoneplace.net/material/polypropylene/)
- [PTFE](https://atoneplace.net/material/ptfe/)
- [Rigid PVC](https://atoneplace.net/material/pvc-rigid/)
- [HDPE](https://atoneplace.net/material/hdpe/)
- [Epoxy resin](https://atoneplace.net/material/epoxy-resin/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)