It's caused by the alloying elements of the stainless steel, y'all!...Chromium
Typically 16.5% - 19.5%. Used to impart stain and corrosion resistance to the alloy.
The chromium carbides created in the alloying process are VERY hard, and difficult to cut with less than the harder of the abrasive materials.Nickel
Typically 10.5% - 13.0%. Used to impart stain and corrosion resistance to the alloy. Provides even greater stain and corrosion resistance when alloyed in conjunction with chromium.
The nickel in the alloy causes it to have a pronounced 'stickiness' in the cut, creating a tendency for the cutting tool to be 'dragged' into, or 'thrown' from the cut.Molybdenum
Typically 2.5% - 3.0%. Used to impart abrasion resistance and impact strength (toughness) to the alloy.
The abrasion resistance imparted to the alloy by the inclusion of a small percentage of molybdenum will cause the cutting tool, or abrasive, to have a tendency to 'skate on the surface' rather than bite into and cut the alloy.
Thought y'all might wanna know!...