Specifically, the refractory metals within this group are incredibly hard. Some examples include:
* Chromium (Cr)
* Molybdenum (Mo)
* Tungsten (W)
* Tantalum (Ta)
* Rhenium (Re)
These metals are extremely resistant to wear and tear, making them ideal for applications where durability is essential, such as cutting tools, engine parts, and high-temperature applications.
It's important to note that "hardness" is a complex property and can be measured in different ways. For example, tungsten carbide is a compound, not a pure metal, but is often considered the hardest material known.
