Although tungsten does have a well-deserved reputation for being an incredibly durable material, there are a couple caveats that buyers should know about before buying a tungsten carbide ring or other piece of jewelry.
Tungsten carbide cannot be resized, so it helps to choose a size carefully, or to find a seller that offers free replacements if necessary. If you're not planning on gaining or losing much weight, you'll probably be fine.
The metal is denser than lead, meaning tungsten rings are often quite heavy. Some people prefer the extra heft, but it's just something to be aware of ahead of time.
Stay away from cobalt content, which can cause allergies and eliminate the hypoallergenic advantage of tungsten carbide rings.
They can't be engraved by hand, so you'll need lasers instead. This is not particularly hard to find, but keep it in mind.
Finally, although tungsten rings are more difficult to cut off than other materials, it's still possible to cut them from a finger if they get stuck; it generally requires more serious equipment, but it can be done.