Blade Change Intervals

[OutdoorEnvy]

The blades really are not dull.
They are dipped in a heavy paint.
Why you ask? So that when a person that is careless installs the blade they do not cut them selfs.
They are as sharp as they need to be.

I asked because I thought maybe the paint was more to protect it from rusting in storage until it's sold or something. I was just surprised that a new blade isn't very sharp.

 

[bertsmobile1]

Now to get a little exoteric, there is nothing that is really sharp, they are just less blunt.
The actual thickness of the leading edge is a compromise between thickness which is needed to support the blade and thinness which improves the cutting rate & finish.
Too thin & the edge will chip dent and dull very fast.
Too thick & it puts a greater load on the engine and bashes the ends off the grass.
For push mowers some where around .040" tip diameter is near ideal.
It used to be thicker but the maximun permissible blade tip speed is continual being reduced in order to make mowers more safe ?

 

[tigercat]

On the residential machines, I grind the edge to a sharp by feel edge. The blades spin slower so it helps the grass look and motor run with less torque. I do these once a year when I do the full service on them.

On my Scag I run it on my property and neighbors yard so it gets several hours a week. In the fall it works a lot harder but still a fraction of use compared to a dedicated lawn care business. I sharpen the blades almost as sharp as the residential machines and they also get done once a year after the fall clean up is finished. They look good but I still grind them some to keep the edge as I like them.

So to a machinist eye I grind the residential blades to .005 thousands edge and the big Scag to .020 thousands edge. Mostly blue grass here, a few rocks. I cut at 4" level to avoid the rocks and tree roots as much as possible.

I'm guilty of sharpening new blades out pf the package also....:laughing:

 

[bertsmobile1]

Those edges are a bit on the fine side but obviously work well for you.
I wish I could get you to talk to some of my customers who insist on mowing their grass at 1/2 with a rotary mower .
For those who need to cut that low they make drum mowerers.

At thoes heights you are obviously getting away with the fine edge and your lawn should look & feel great.
The finest edge recommended by any bar blade maker is 0.125 ".

 

[tigercat]

With the grass too short you just burn the grass in the summer. I don't water my grass and it stays green all summer long, unless we have a super hot dry spell. I started striping the yard and it's nicer when the grass is longer also.
Third, the blades get destroyed when they hit hard stuff...Sharpened blades get all bent, dinged up. I finally wised up after all these years and raised the deck:laughing:!