When would you replace mower blades (B2601)

[PaulL]

So, I've purchased new blades, but I feel like the old ones still have life in them. I had them off to tighten and sharpen today, here's the three worn ones, plus a new one for comparison. Am I right that I'm still a way off needing replacement? The ends are starting to curve a bit, which I presume isn't good, but still not so bad I'd switch them out?

Of course, I've had 2 years out of them, and I'm mowing some community land and roadside that means we scalp a lot, and sometimes mow up gravel or other stones....they get sharpened a lot. Perhaps 2 years is about all the life I should expect.

Second question - the new ones aren't particularly sharp. Would you sharpen them before fitting, or is that actually sharp enough?

 

[Motion]

Personally, I'd say it's time to retire them. I wouldn't sharpen the new ones (the factory may know what's doing) you never really want a real sharp edge. Consider having two sets so you keep mowing and dress the other set at your convivence. As always do as you feel is best.

 

[GreensvilleJay]

I'm on the other end of the teeter-totter...

LOTS of life left in them,heck the uplift sections are still there ! Just be sure to balance them !

'yes', factory know what they're doing... selling dull blades that wear out sooner, so you can buy more dull blades , that wear out sooner that........

Do you shave will a dull straight razor ?
Do you chop wood with a dull axe ?

 

[lynnmor]

I think the dull new blades are more about safety and shipping. I sharpen and balance before use.

It appears that the old blades were ground more at the ends, try to remove material evenly over the length of the cutting area. Take note of the angle on the new blades, the old ones are ground at too steep of an angle.

 

[mikester]

I have sandy soil and manage only about 1 season. They get sand blasted paper thin and the cutting edge gets wavy. Yours look not too bad.

 

[mcfarmall]

I'd run the old ones until the sand cuts a slit in the wing. When they get forked I replace.

 

[Smokeydog]

After sharpening to get the right angle, I blunt the cutting edge 1/32”. Blades stay sharper longer. Loss of material at the tip is usually the factor in replacing blades. 1/2-1” at tip cuts 90% of the grass. Detail in Woods mower maintenance manual.

 

[D2Cat]

The sharper the blade, the quicker they dull. Just like your pocket knife. You can get it sharp enough to shave the hairs on your arm and slice a sheet of paper, but it doesn't take long before it won't!

Sharpen a blade to suit your thinking, but be sure to balance them before installing.

What did you mean to take the blades of to tighten them?

 

[Mowbizz]

I would use them for one more sharpening but get a better sharpening angle as others said. It doesn’t sound like you’re mowing for a manicured look…use them until they don’t do the job anymore.
I have a sharpening jig I use to get the right angle and a balancer as well. When I sharpen, once the edge is sharp enough, I lightly run the grinder flat against the edge as it is spinning to a stop. This creates a tougher edge that still cuts adequately for my usage.

 

[PaulL]

What did you mean to take the blades of to tighten them?

Last time I sharpened I didn't tighten the bolts enough. When I mowed very heavy (and a bit wet) grass the other day a couple blades were spinning on the shaft. I had the mower off to do some loader work, and thought I may as well tighten those bolts. Which turned into I may as well sharpen those blades, even though they weren't too bad.

 

[PaulL]

After sharpening to get the right angle, I blunt the cutting edge 1/32”. Blades stay sharper longer. Loss of material at the tip is usually the factor in replacing blades. 1/2-1” at tip cuts 90% of the grass. Detail in Woods mower maintenance manual.

Useful information, and I was assuming this would be the case - logically the outside will get to the grass first.

My blades are self blunting, so I don't really need to blunt them after sharpening. I'm generally getting 6-10 hours of mowing before I sharpen, which is about 4 - 6 weeks.

 

[bird dogger]

I agree there's still some life left in your older used blades. I use blades in that shape for the first few mownings in the spring!! Finding the stones, debris, etc. that's left over from winter snwoblowing into the yard with the old blades doesn't irk me so much. And especially mowing the roadside ditch the first few times when you inevitably find and run over some trash, bottles, etc. hidden in the grass.

After a couple of mowings and the yard, ditches, etc. have all been cleaned up.....it's time for the nice newer blade to be put into service!