Semi-related: Is it possible to boost skills beyond 100 points?
I bring this up because I just found the http://elderscrolls.wikia.com/wiki/Notched_Pickaxe.
I did test this myself, and I didn't seem to see any difference in improving my armor. Also note that the wikia page for the pickaxe specifically states that it can't be improved over 100.
Just want to verify with you guys, thanks!
Thanks for the quick answers. Not only is it possible, you can disenchant the Notched Pickaxe and get 10 extra smithing points by enchanting it onto 2 weapons we can be dual wielded.