SRD:Align Weapon

Align weapon makes a weapon good, evil, lawful, or chaotic, as you choose. A weapon that is aligned can bypass the damage reduction of certain creatures. This spell has no effect on a weapon that already has an alignment.

You can’t cast this spell on a natural weapon, such as an unarmed strike.

When you make a weapon good, evil, lawful, or chaotic, align weapon is a good, evil, lawful, or chaotic spell, respectively.