Bingo! Hardness is only one factor. As steel gets harder, it may hold an edge longer, under certain conditions, but also becomes harder to sharpen with a file in the field. It also becomes more brittle at a point, which means that the fine cutting edges can break off easier.
Same thing with 'thicker chrome', which some guys assume means a 'better chain'. Chrome provides abrasion resistance on the top and side of the cutters, but it is also hard / brittle, and cannot be practically sharpened, so a cutter with thicker chrome can not be made as sharp as one with a thinner layer. Some racers try to remove the chrome layer for race chain.
Overall, chain manufacturers have to balance: hardness, toughness, durability, heat treating, finish, corrosion resistance, alloys, material costs, manufacturing methods and costs, environmental issues (chrome plating), geometry, markets, etc., etc., etc. You can focus on any one of these and come up with the wrong choice.
Best thing is to buy a few loops, of different types / models / brands, etc, that fit your saw, and see which best meets your needs under your cutting conditions. Then, start messing around with different sharpening angles! Nothing wrong with having different chains for different types of wood or cutting conditions either - think of your saw as a socket set, and use different chains and guide bars like sockets and extensions for the work at hand!
Philbert
