Cryogenic hardening is a process that uses cryogenic temperatures to strengthen and enhance the grain structure of a metal. Without going through this process, the metal can be prone to strains and fatigue.

The process of cryogenically treating a metal part involves very slowly cooling the metal using gaseous liquid nitrogen. The slow cooling process from ambient to cryogenic temperatures is important in avoiding thermal stress. The metal part is then held at a temperature of around −310 F.
(−190 C.) for 20 to 24 hours before heat tempering takes the temperature up to around +300 F. (+149 C.). This heat tempering stage is critical in reducing any brittleness that may be caused due to the formation of martensite during the cryogenic treatment process.
Cryogenic treatment changes the entire structure of a metal, not just the surface. So the benefits are not lost as a result of further processing, such as grinding. 

Buying a premium blade, like the Ballister Professional blades, may seem like an unnecessary expense, when you can buy standard blades for less than half the price.

We believe that buying cheaper bades is a false economy. Modern carpet backings contain much more filler than they used to. The filler used in carpet backing is usually chalk, and chalk kills standard blades made of lower grade steel because it is very abrasive. Any fitter will tell you that they encountered carpets that had so much filler in the backing, that a standard blade only lasted one wall, so they had to use 4 or 5 blades to fit one room, or that they went through 20 blades to fit 3 bedrooms, stairs and a landing. The cost of using cheap blades quickly adds up, especially if you count the fact that you have to continuously stop fitting to change blades, and we're not even counting the physical additional effort needed to actually cut the carpet with a blunt blade.

We say that it is time you bought a better quality blade, so that you can spend more time fitting and less time changing blades. You'll most likely end up spending less on blades, in the long run, and the fact that you are using blades that actually cut, will make your working day more enjoyable.