Step 9: Blade hardness
The hardness of the blade is measured using the Rockwell Count scale (RC scale). It is determined by teh heat treating of the blade as it is made.
High hardness (~ RC 60-65):
This is more brittle, but holds an edge very well. Impacts may cause the blade to chip, so it is suited for small knives and general cutting.
Medium hardness (~ RC 58-60):
This is suitable for a wide range of tasks, and is what you would want for a general purpose survival knife. It holds an edge fairly well.
Low hardness (~ RC 52-58):
This is the least brittle, but does not hold an edge as well. It is used for impact blades, such as meat cleavers and axes.