I sometimes peen scythe blades for local scythe people that don't want to peen their own. I see a lot of damaged edges doing this. Most damage occurs when the blade is dull and the owner compensates for that by swinging harder and chopping at the grass. The leverage on the tip of the blade from this force, often pushes the tang to the back of the ring, which opens up the tang angle all the way, and then the full force of the blow hits the edge of the blade straight on, instead of the acute shearing angle it was meant to. If the edge hits a rock straight on like this, you can cause considerable damage, as shown in the picture above. If you keep mowing with this kind of a crack, the crack can snag on an object, and increase the damage.