When you use a sunder weapon, you get a +2 weapon bonus on Might checks when attempting the Sunder combat maneuver. In addition, if your sunder combat maneuver is successful, add +2 to the damage inflicted by the combat maneuver. Sunder weapons can be used to make sunder attempts against unattended objects, structures and fortifications, including those made from metal or stone.
Note: Weapons made from special materials often have bonuses or penalties to Sunder checks. These material bonuses and penalties stack with the weapon bonus to Might checks granted by a sunder weapon.