Does gray cast iron float?
Does gray cast iron float?
No
7,150 kg/m³ against water's 1,000
Gray cast iron sinks. At 7,150 kg/m³ it is 7.15 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
- 7,150 kg/m³ (7,050–7,300)
- Relative to fresh water
- 7.150×
- Floats in fresh water
- No
- Floats in seawater
- No
Compared with other materials
| Material | Density | Floats |
|---|---|---|
| Ti-6Al-4V titanium alloy | 4,430 kg/m³ | No |
| titanium | 4,506 kg/m³ | No |
| 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 |
Common questions
- Does gray cast iron float in water?
- No — at 7,150 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
- Gray cast iron properties Density, melting point, strength
- Does air float? Yes
- Does expanded polystyrene foam float? Yes
- Does rigid polyurethane foam float? Yes
- Does EVA foam float? Yes
- Does balsa float? Yes
- Does corrugated cardboard float? Yes
- Does cork float? Yes
- Does western red cedar float? Yes
Sources
- Typical range compiled from manufacturer specifications — At One Place