On 1 April2009, Jagex officially changed the names of all Woodcutting "axes" to "hatchets".
Prior to the removal of free trade, hatchets would lose their metal head, and you would have to re-attach them to the handle before being able to continue woodcutting. This was considered a random event designed to combat bots.
Before the release of the dragon hatchet, the rune hatchet could be used to cut down trees at any Woodcutting level, but this was changed to prevent macros from using them immediately after the creation of their account.