The industry now knows about several methods to harden steel using different elements like austenite for the case of martensitic steel grades. The addition of carbon allows to play with the characteristics of the alloy for different applications.
The hardness implies resistance and with it, the natural game of strength that damages weakness. So if you use a ferritic steel tool to cut a certain diameter of a martensitic steel grade, it will break or experience a deformity because its lower resistance.
Martensitic steel uses appear in gears, dental tools, springs, fasteners and alike where resistance is important. It's common to see this steel with a polished finish due to be more prone to oxidation and corrosion without the treatment. That solves the problem effectively proving it superior for some areas.
Different manufacturers provide a detailed steel specification; this way the user could know what is buying, and having an idea about the fairness of the price. Martensitic steel is ASTM 400 series.