What is red hardness What is the importance of red hardness

What is red hardness ? What is the importance of red hardness in drilling operations with steel ?

Solution

Red hardness may be defined as ability to resist softening when exposed to heat while in operation.(especially defined for steels).

Importance here is that the tool may get softened if the red hardness of the steel is less which may cause premature failure and also red harness can be improved in steel by adding tungsten,cobalt or both.