Blades made of Russian chromium-tungsten tool steel with very high hardness and wear resistance.

Blades made of XB5 steel (XB in the Cyrillic alphabet, which would be written as HW5 in the Latin alphabet), also colloquially known as "almazka" (diamond steel). This is a Russian chromium-tungsten tool steel characterized by very high hardness and wear resistance. A blade made of this steel holds an edge for a very long time and is excellent for skinning, cutting tendons, and bone work; however, it should not be thrown or subjected to bending. This steel contains chromium (around 1%), making it less prone to corrosion than Damascus, but it is not entirely stainless.