On Thursday, January 23, 2020 at 2:59:50 PM UTC-5, Thomas wrote:
Must be one big hammer...

No. I would guess (it's been a while) a 3 pound hammer, 1/2 to 5/8 inch bolts.

You'd be surprised how brittle they are. Hit them fairly hard and they snap instead of bending. Never had to grind one down like you would if you used a cutoff saw.