Terraria (Wiki): Combat Wrench

The Combat Wrench is a type of thrown melee weapon that returns to the player after damaging an enemy (pierces one at close range), traveling for 19 tiles away, or hitting a solid object.

When normally used, the Combat Wrench will not emit light. It also phases through any type of block when returning to the user. The Combat Wrench can also squeeze through one-block-wide gaps at the right range. When used on liquids, the Combat Wrench’s travel speed and range drastically decrease.

It is a general rule to aim above enemies for unlimited piercing when using the Combat Wrench. This unique property is possible thanks to all Boomerang’s capability of phasing through walls. One can easily handle a wave of slightly strong enemies and deal low knockback with Combat Wrench.

At the right range, enemies will receive two consecutive damage as the Combat Wrench goes to the target and back to the player. Damaging enemies on both ends of a wall is also possible when executed at the right position and range. This unique property makes the Combat Wrench pass through walls unhinged while keeping hostiles at bay.

As more enemies approach, the player could get in close range and land consecutive attacks, as the weapon’s use time is determined once the boomerang returns.

Since the Combat Wrench is a melee weapon, some accessories, all flasks, and armor can enhance its travel range, flight speed, and apply flask-related buffs.

Because of the Combat Wrench's average travel distance, it is an underwhelming option when dealing with fast-moving aerial enemies. However, because of the Boomerang's piercing capability, it is good against hostiles with segmented bodies and some Pre-Hardmode bosses like The Eater of Worlds.

The Combat Wrench is best modified with Godly or Demonic, providing a wide array of stats improvement.