Bent Snapper 17168 20-1/2" Mower Blade

[sleddriver]

This is the same Snapper given to my by a neighbor. I mentioned it here in an earlier thread.

I pulled the blade to resharpen and while on the balancer, noticed both ends closer to my bench than the middle; like the blade is 'drooping' at each end!

Is this a Snapper thing?

I put it in a vise and attempted to bend it back, but no joy. Then I blocked up each end and stood in the middle (I weigh 250lbs). No joy there either.

Here's some photos:

I laid the blade on top of the fence and my straight edge on top of the blade. The straight edge rests flat in the middle and you can see the further away from the center, the more the blade 'droops'. Likewise, the middle is lifted off the fence board by the two ends.

Another view:

This seems very odd.

It doesn't cut grass very evenly like this. It's better with a sharp edge of course.

Any ideas how to straighten it myself? Use a torch? Put it in a 450°F oven? Take it to a metal worker?

 

[Corvette Owner]

Buy a new blade, not that expensive. But first, look at new blade to see if it is the same.

 

[Propflux01]

+1 on New blade. Don't even think about heating, torching and other things of torture to that blade!

 

[crazyoildude]

buy a blade that is balanced but make sure the shaft is not damaged

 

[Kuato]

If it were damaged, there would be large differences between the two sides. I've seen more than one mower blade that wasn't straight across which were not damaged.

I bet the new blade is the same shape.

 

[doitmyself]

If the two ends are equally offset from the center, then there should be no problem. The problem is when the blade hits something, gets bent, and one end is substantially lower or higher than the other end.

Also remember that only the outside inch or two of the blade actually does any cutting (on a non mulching blade). This is because the blade revolves so fast.

I bet your blade was like that new. Other brands may, or may not have the bend.

 

[sleddriver]

I heard back from Snapper customer service. They indicated new blades are straight, save for the back edges of the tips which are 'kicked-up'. Now I'm wondering what happened to this one to cause it to become convex? Oh well...

I did have a bit of luck straightening it after realizing I needed a bigger (and much heavier) "hammer."

Wasn't able to get to a local indy mower shop today before they closed to get a look at a new blade.

 

[grcmptrnrd]

Oregon aftermarket blades for some Toro commercial mowers have the same profile when new. Not sure about the OEM for the Toro.

 

[JTK]

You call that bent?

You should see some after my usage. Kidding!

If the vibs aren't bad, I'd keep using it as-is.

Joel

 

[sleddriver]

This old Snapper was re-engined. I think the original engine seized, so the neighbor upgraded it to a B&S Quantum. Nice motor. Probably never even looked at the blade.

I clamped it down in the middle with some spacers on each end and left it for a few days. Still springs back a bit, but not nearly as bad. I'll have to stick it in my indy's hydraulic press and tweak the ends. Then I'll give it a sharp edge.

 

[sleddriver]

Update: Finally got over to a local mower shop that carried Oregon replacement blades. Turns out my blade is supposed to be curved and is listed as a 'mulcher'. When the new one was plopped on the counter, it was very convex. Very. Looked dam odd actually.

There is also the 'standard' blade, designed for leaf pickup and catcher use. It's dead flat with a long 'kick-up' across the back, evidently to create a high vacuum.

This explains why catcher performance left a bit to be desired recently when shredding leaves. I noticed the chute to often clog, even when the bag was only half full. I only use the catcher to pickup leaves. Rest of the time, mulching will be great.

 

[Fleetmon]

i think I'd be replacing the old blade after your attempts at straightening it.....the LAST thing you want is a blade breaking and/or coming apart. I doubt you'll be able to jump out of the way quick enough!

 

[sleddriver]

Originally Posted By: Fleetmon
i think I'd be replacing the old blade after your attempts at straightening it.....the LAST thing you want is a blade breaking and/or coming apart. I doubt you'll be able to jump out of the way quick enough!

By design, mower blades are made of 'soft' steel designed to bend or deform. If made with a harder, brittle steel they'd shatter with the first rock you hit and that would be really dangerous.