The tomahawk is a thrown weapon. It is a make-shift weapon, and is made out of two railway spikes secured to a pipe with electrical cable and a bungee cord with feathers, paint, and beads for decoration.
Variants
Hatchet - the common variant of small hand axe in Fallout: New Vegas.
Throwing hatchet - a variant of hatchet specifically made as a throwing weapon.
Similar to the throwing spear, this weapon will stick in the ground, walls, etc., but cannot be retrieved after being thrown.
If the player is hit by a tomahawk, it is visibly sticking out of them in third-person. However, after approximately 5 seconds, it will disappear.
The tomahawk has very high item health relative to most other melee weapons, and as such would degrade very slowly, even though you can only attack once with it as it becomes unretrievable once thrown.
Bugs
xbox360ps3 When holding more than 30 tomahawks, it will show that you only have a small amount. However, if you drop the small amount, it will then say you have 30, much like the throwing spear.
ps3 In first person you will not have a tomahawk visible in your hand, but if you throw one, you will still have the same amount, effectively creating an infinite number of tomahawks.