Note: I'm not sure what the max damage is. The max damage given is for a character with Strength 96 and Blade skill level 76. This item has probably stats of enchanted daedric longsword, and it's leveled weapon, so on low levels stats won't be so impressive.
I'm level 47 with strength 100 and blade 100. And I got the Thornblade with a base damage of 26.