Blades Warped blades. What causes?

[billkater]

I have a Ariens EZR1648 zero turn mower. Last year I purchased 2 sets of blades for it from a local farm supply store. They are Stens blades. I took the first set off today to sharpen and they are warped. Both ends of all 3 blades raise 1/8 - 3/16 of a inch on each end. I got the second set of blades out (never installed). And the lay flat all the way across. I dug out the original set and they are almost level.

I have been getting a stripping effect when I mow and I am sure these blades don't help. So my question is as stated;

"What caused my blades to warp?"

 

[mowerbeast]

Could be that you hit something, but I think you would know if you did. The blades could be made of cheap materials that is bending easilly.

 

[billkater]

Could be that you hit something, but I think you would know if you did.

I am very careful when mowing. Pick up all sticks and such before I start. Even if I did hit something I could not see it bending all three blades.

Anyone else have problems with Stens blades?

 

[benski]

I've had some of the thinner style blades warp from hitting the grass inside a clogged deck. I couldn't initially believe it, but that was my experience.