I took apart a brand new HF Chicago Pneumatic medium barrel air hammer as I was curious what was inside, how complicated it was inside to require a "special" air tool oil.
There was nothing inside, nothing complicated. I unscrewed the black barrel, inside there was a flat round disk with alignment holes that pushes against a small piston 1/2" x 1 1 /2" that drops inside the barrel. The trigger allows air into the barrel of course. I used synthetic oil on the moving parts and reassembled. There's no reason to use a special oil.
I don't know if a more expensive air hammer is more complicated.
There was nothing inside, nothing complicated. I unscrewed the black barrel, inside there was a flat round disk with alignment holes that pushes against a small piston 1/2" x 1 1 /2" that drops inside the barrel. The trigger allows air into the barrel of course. I used synthetic oil on the moving parts and reassembled. There's no reason to use a special oil.
I don't know if a more expensive air hammer is more complicated.