On Sun, 11 May 2014 06:11:01 -0700, Jon Danniken
wrote:

On 05/10/2014 04:15 PM, gonjah wrote:
On 5/6/2014 11:49 AM, wrote:
On Tue, 06 May 2014 09:14:36 -0400, "(PeteCresswell)"
wrote:

Per Jon Danniken:
I used a 6" bench grinder, and no blue either.

My blades are time consuming to remove/replace so I've gone over to a
little attachment to my Dremel tool: turn the mower on it's side, run
the Dremel... and it's done.

But next time I am going to finish off with a light pass perpendicular
to the edge to give it that flat area that Clare mentioned.
The "square" edge effectively provises 2 curring edges.


Mine must not be very "hardened" because I simply run the gas out and
take the spark plug out. Then I take an old hand file and run over the
blade a bit. Seems to work just fine. I probably should balance it but
I've never used anything other than a hand file. I used to take the
blade off, but it just seemed like a waste of time.

The last thing you want is a hardened mower blade, as it would be too
brittle to be run safely at the speeds a mower blade is run at.
Instead, it is designed to deform when it strikes an unexpected item,
instead of sending chunks hither and yaw.

Jon
They are generally hardened and tempered - whick allows them to keep
a reasonable edge and not shatter.