measuring up cheap blades rockwell hardness

[rodney]

metal hardness is measured in rockwell hardness units , and the hardness of a blade ranges from 35 on the low end to 50 on the high end some blades may go higher. example is stens carbide tongsten blade has a hardness of 65.
the higher the hardness value the longer the blade will retain a decent edge .
you pay more for harder blades but you pay even more for the cheaper blades , by spending more time shapening and replacing them.

i fond this in grounds maintenance magizine.

so i whent to the barn to get some blades to see what thy are and couldnt find but one blade out of greatdane ,lawnboy, toro and snapper that has a two didgit number. the snapper has a square box next to the numbers 80k .

is this rite do they make them that hard and why are the other blades not marked ?

[ceaman]

That is not the rockwell hardness, I guarantee it.

The abbreviation for rockwell hardness would be something like 50Rc which states that it is "50 on the rockwell C scale".

[longslawn]

I agree with ceaman. I worked as a machinist for 16 years and if the blade was 65 rockwell it would be very dangerous to use. I once tested a John Deere blade and the Rc was 26. I would think that most blades were this or less.
We worked with tool steel and only got rockwells of 62-68.
I don't think the blade steel is of tool quality and could not reach these Rc numbers. It could be case hardend, but I dought it. It would be a pain to sharpen a 65 C blade.

[shadetree]

Silver Streak has a number of blades that are now rc50.
I use their Gator magnum rc50 and have very good luck with them.