Do you have to sharpen new lawnmower blades?

[sh00ter]

I'm specifically talking about mulching blades for a lawn tractor, but same applies to all lawnmower blades. They seem to come new dull, and not sure if it is best to put an edge on them or leave them as they come. When I have used them straight from the box in the past, once it is time to re-sharpen, I always put a better edge on them so I wondered if maybe the lack of a "razors edge" on lawnmower blades is intentional from the factory?

 

[Mr.Glock]

I have never. I also know they need to be left thick, not sharp. Same on a brush hog.

 

[bigred1]

No need to resharpen. The factory angle is best. You try to make them razor sharp and they'll chip and wear out a lot faster..

 

[bigred1]

@Mr.Glock beat me to it.

 

[kingfish]

A razors edge won't last long, depending on the hardness of the steel, that edge will be gone in one or two uses. My test for proper blade sharpness is when I drag my fingers across the edge, I like it to feel like it's just starting to grab the skin rather than sliding over it. Anything beyond that won't last long. I prefer to use a file to sharpen my blades vs a grinder. Grinders overheat the metal and take the temper out of it which makes the blade get duller quicker. When I get it down to the original edge angle, I increase the bevel angle to make the edge a little tougher and longer lasting.

 

[rickm]

On my mulching/ bagging blades i never sharpen them i will usually wear the back fin out before they really need sharpening so i just replace and i mow lawns as a spare gig, now my other mower that i use in big heavy stuff that has a lot of dead branches and small saplings i will resharpen them about once a year.

 

[Chuckie]

More important than sharpness is to make sure the blade remains relatively balanced.

 

[Bocephus123]

Just beat the grass to death

 

[CutBaitNBlowSh*tUp4ALivin]

...and i mow lawns as a spare gig...

...I am in desperate need of a small, working riding mower...

@RickN @rickm
How have y'all not connected before? Feel like y'all'd be two peas in a pod

 

[Buddhaman]

I watched a Project Farm on blade sharpening tools. He mentioned 30 degrees being ideal and aside from the expensive grinder, a hand file was cheap and effective. I’ve never sharpened a blade on a new mower (or blade for that matter) but am ready to sharpen the one that’s in my mower. I’m not sure if a mulching blade matters as far as sharpness goes. Guess I’ll see what any Honda forums say about that.