Mike,
In Boo's defense, he was trying to bring a bit of comedic interaction. He'll grow on you. If not, just punch him in the teeth and then you two can share a beer and all will be forgotten. lol
That is close enough to be the very same machine as my 1996 MTD Yardman All Wheel Steer. Mine is a 7 speed or seven slots for the variable speed pulley adjust to stop in. I prefer to call this set up a variable speed mower. Mine too is a 42" cut and low and behold after 21 years, I bent the living crap out of one blade. The blades are original blades, been sharpened one time and they were sharpened and honed to clear cut my arm hair. Boyeeeeeeee did they cut nicely.
What my neighbor hit was not seen at first in the tall combination grass and overwhelmingly heavy weeds. He couldn't get it started afterward so I had to go rescue it. Once I lifted the deck off it, it turns out to have been a truck axle driven into the ground for a corner stake. Did I mention the mower stopped immediately? At least that's what the neighbor said. I heard it from my house 300 feet away. I have loaned the mower out twice and determined that wouldn't happen a third time.
Last year, my oldest brother was in hospice and thus I mowed his complex for him when I would be in the state. Grass was always no less than 20 inches and more before I could get the mower back out there to cut. Each time I went out there, I'd find a dog auger tie with the deck, a hole dug just wide enough to drop a tire in with another hole hiding a full roll of 1/8" coated wire rope. I can tell you right now that wire rope or if you're like me, "cable" will stop a deck and any forward movement immediately. It took about a hour and a half to get the mower unwound and able to start again. Not of these latter situations bent the blades, however, the now look like a serrated knife. I just sharpened them to a razor edge and put it back to work once they were balanced.
The truck axle did bend it and it refused to be straightened at home without a torch and a big vise. However, a torch does NOT belong near a mower blade.
So, the blades can be bent. What will bend them in one case that didn't in the next does not always allow explanation.
Hope you get a long life out of your MTD. Mine runs like a "Deere", steers like a Rolls Royce and looks like hammered Shyte!
Max