Stone Fence taking longer than usual to remove with Stone Axe or Pickaxe.

First I built a wooden fence to see how fast it gets taken down with a Stone Axe and Pickaxe. I was able to chop the fence fairly quickly. Not so much with the Pickaxe. I made the Stone Fence and tried to chop that and it was slow... understandable. I used the Pickaxe and it was still the same speed as if I were chopping it with the Axe.

What I expected to happen was...:
Stone Pickaxe to destroy the Stone Fence at the rate of speed as if I was mining stone out of the walls.

What actually happened was...:
Stone Pickaxe and Stone Axe were the same speed at removing the fence.

Steps to Reproduce:
1. Build a stone fence. Wood fence if you want.
2. Compare speeds or examine speed of the Stone Axe and Pickaxe against the fence.
3. N/A