D&D4 Wiki
Attack bonus if proficient +2
Weapon die ([W]) 1d6
Type melee
Range 5/10
Handedness one-handed
Proficiency category military
Weapon group
Weapon properties off-hand, heavy thrown
Price 5 gp
Weight 3 lb.

A handaxe is a military one-handed melee weapon in the axe weapon group.[PH:218]

A handaxe is an off-hand weapon. A character can use a handaxe to make attacks even while holding another one-handed weapon in the other hand, and can use the other one-handed weapon to make attacks even if it isn't an off-hand weapon. It is also a heavy thrown weapon, so a character can throw it to make ranged attacks, using Strength instead of Dexterity for ranged basic attacks.

Ardents, avengers, barbarians, battleminds, fighters, paladins, rangers, wardens, and warlords are proficient with all military melee weapons, including the handaxe.

Other classes do not have proficiency with the handaxe as a class trait, but any character can become proficient by taking a Weapon Proficiency feat.