---
title: "Does high-carbon steel float in water? No"
description: "High-carbon steel sinks — its density is 7,850 kg/m³ against water's 1,000. Why density and not weight decides it."
url: https://atoneplace.net/does-it-float/carbon-steel/
site: "At One Place"
---

# Does high-carbon steel float?

**Does high-carbon steel float?: No**

7,850 kg/m³ against water's 1,000

High-carbon steel sinks. At 7,850 kg/m³ it is 7.85 times denser than water.

## Why

Floating is decided by density alone — mass divided by volume — compared against the fluid. Weight has nothing to do with it directly: a 200-tonne ship floats and a 2-gram pebble sinks, because the ship encloses enough air to bring its average density below that of water. That is also the only reason a steel hull works.

## The numbers

- **Density:** 7,850 kg/m³ (7,800–7,900)
- **Relative to fresh water:** 7.850×
- **Floats in fresh water:** No
- **Floats in seawater:** No

## Compared with other materials

| Material | Density | Floats |
| --- | --- | --- |
| ductile iron | 7,100 kg/m³ | No |
| zinc | 7,140 kg/m³ | No |
| gray cast iron | 7,150 kg/m³ | No |
| chromium | 7,190 kg/m³ | No |
| pewter | 7,300 kg/m³ | No |
| tin | 7,310 kg/m³ | No |
| lead-free solder (SAC305) | 7,380 kg/m³ | No |
| wrought iron | 7,700 kg/m³ | No |
| tool steel | 7,800 kg/m³ | No |
| high-carbon steel ← | 7,850 kg/m³ | No |

## Common questions

### Does high-carbon steel float in water?

No — at 7,850 kg/m³ it is denser than water's 1,000.

### Does weight decide whether something floats?

No, density does. A 200-tonne ship floats and a small pebble sinks, because the ship encloses enough air to bring its average density below water.

## Related pages

- [High-carbon steel properties](https://atoneplace.net/material/carbon-steel/)
- [Does air float?](https://atoneplace.net/does-it-float/air/)
- [Does expanded polystyrene foam float?](https://atoneplace.net/does-it-float/eps-foam/)
- [Does rigid polyurethane foam float?](https://atoneplace.net/does-it-float/polyurethane-foam/)
- [Does EVA foam float?](https://atoneplace.net/does-it-float/eva-foam/)
- [Does balsa float?](https://atoneplace.net/does-it-float/balsa/)
- [Does corrugated cardboard float?](https://atoneplace.net/does-it-float/cardboard/)
- [Does cork float?](https://atoneplace.net/does-it-float/cork/)
- [Does western red cedar float?](https://atoneplace.net/does-it-float/cedar/)

## Sources

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