Tungsten Bars are a type of bar crafted using 4 Tungsten Ore at a Furnace, and are used to make Tungsten-themed items.
Tungsten-tier equipment, like most other alternative metals with the exception of Tin in some cases, is slightly better than its counterpart Silver. This makes it a bit more valuable in terms of helping the player survive, explore, and build.
Crafting all Tungsten equipment, including the Watch and Chandelier, requires 151 bars, or a total of 604 ore. Without the Watch and Chandelier, 137 bars or 548 ore will be required.
The word tungsten is made out of the Swedish and Danish words tung ("heavy") and sten ("stone").
In reality, tungsten is extremely difficult to work due to its hardness; it has one of the highest melting points of the elements. It also is used in the filament for light bulbs due to its heat resistance.
Furthermore, real-life tungsten is actually a white metal, not green.