Because they are more dense than water.
Iron nails sink because they have a high density and a small volume, which means they displace less water relative to their weight. In contrast, an iron ship is designed with a hull that encompasses a large volume of air, making its overall density lower than that of water. This buoyancy allows the ship to float despite being made of the same material as the nails. Thus, the shape and volume of an object determine its ability to float or sink.
they are steel, steel sinks
The general rule is that an object will sink if it has a greater density than the liquid in which it is placed.
Maple syrup will sink but water is unable to sink because it is water.
It's thought that Archimedes, the ancient Greek scientist, used lodestone to pull nails from enemy ships in war to make them collapse and sink.
the water sink is not solid and liquid
Arsenic is denser than water, so it will sink in pure water.
Silicon will sink in water because it has a higher density than water.
Nails do not rust in water. Nails only rust in water if oxygen is present. This is because the iron in nails react with oxygen and water to form a compound called hydrated iron(III) oxide.
If you're speaking about nails as in "hammer & nails" then the effect of water and oxygen will eventually corrode them by rusting.
Sink water or water without salt.
Rocks sink because they are denser than water, causing them to displace less water and therefore sink. Metal objects sink due to their high density, which makes them heavier than water and causes them to sink. Sunken ships sink because they take on water, increasing their overall weight and causing them to sink below the water's surface.