---
title: "Nylon 66 — density, melting point and properties"
description: "Nylon 66 has a density of 1,140 kg/m³ (1,130–1,150). Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/nylon-66/
site: "At One Place"
---

# Nylon 66

**Density of nylon 66: 1,140 kg/m³ (1,130–1,150)**

1.14 g/cm³ · 71.2 lb/ft³

Melts about 40 °C higher than nylon 6 and holds its stiffness closer to that point, which is why anything living in an engine bay is nylon 66 and usually glass-filled on top. It absorbs slightly less water than nylon 6 but the same warning applies: dry the granules before moulding or the part comes out streaked and weak. Glass filling at 30% roughly doubles the strength and halves the thermal expansion, at the cost of all the toughness.

## Properties

- **Density:** 1,140 kg/m³ (1,130–1,150) — 1.14 g/cm³
- **Melting range:** 255–265 °C
- **Tensile strength:** 70–90 MPa
- **Young's modulus:** 3 GPa
- **Thermal conductivity:** 0.25 W/(m·K)
- **Thermal expansion:** 80 µm/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Under-bonnet automotive parts
- Electrical connectors and terminal blocks
- Tyre cord and airbag fabric
- Toothbrush bristles and zip teeth

## 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
- nylon 66: 1,140 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× |
| nylon 66 ← | 1,140 kg/m³ | 1.14× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Nylon 66 contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

Nylon 66 is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of nylon 66?

1,140 kg/m³ (1,130–1,150), or 1.14 g/cm³.

### Does nylon 66 float?

No. At 1,140 kg/m³ it is denser than water.

### Is nylon 66 magnetic?

Nylon 66 is not a metal and has no ferromagnetic response.

## Related pages

- [Does nylon 66 float?](https://atoneplace.net/does-it-float/nylon-66/)
- [PLA](https://atoneplace.net/material/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/)

## Sources

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