Chainbreaker Longsword 2014
Weapon, rare
You gain a +1 bonus to attack and damage rolls made with this magic weapon. When you use this weapon to attack or break chains, manacles, or similar metal objects restraining creatures, you have advantage on the attack roll or ability check. In addition, such items have vulnerability to this sword's weapon damage.
Properties
Versatile (1d10)
This weapon can be used with one or two hands. A damage value in parentheses appears with the property—the damage when the weapon is used with two hands to make a melee attack.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details