Actuator

Type	MechanismCrafting material
Dimensions	1 wide × 1 high
Use time	15 (Very fast)
Tooltip	Enables solid blocks to be toggled on and off
Rarity
Buy	10 SC
Sell	2 SC
Research	50 required

A player using Actuators to deactivate a wall of blocks.

The Actuator is a mechanism item purchased from the Mechanic for 10 SC each, or harvested from sand, lava, or Dead Man's Chest traps. It has to be connected with wiring to function. When activated, the tile it is on toggles between active and inactive state, effectively allowing any block to be toggled like active or inactive stone blocks. Like wire, Actuators are normally invisible and only become visible when a mechanism item is selected.

The following items interact with Actuators:

They can be removed with the Wire Cutter or The Grand Design(Desktop, Console and Mobile versions).
They can be placed with The Grand Design(Desktop, Console and Mobile versions).
The Presserator automatically places Actuators on objects when placing them, if the player has any.
The Actuation Rod can toggle any Actuator within a limited range without requiring wire.

Crafting

Used in

Result	Ingredients	Crafting station
Actuation Rod(Desktop, Console and Mobile versions)	Actuator50 Any Iron Bar10 Wire10	Iron Anvil or Lead Anvil

Notes

Actuators can be placed by hand.
In addition to most blocks and traps, Actuators can also activate on teleporters and platforms.
Most furniture on top of a block/platform with an actuator will be freed when the actuator activates.
Actuators will not activate if they are directly beneath a tree, Demon Altar, Crimson Altar, Lihzahrd Altar, or any chest (regardless of whether it contains items or not). (Desktop, Console and Mobile versions) This block actuator protection is present on the 2nd layer of blocks under a chest as well (4 blocks total).
Any plants growing on a block which is put into its inactive state by an actuator will be destroyed as if a tool was swung at it. This can be used to harvest mushroom farms. Herbs and Moss, however, will remain on the inactive block.
Liquids and falling blocks like sand, silt and slush can pass through blocks which an actuator has made inactive. On the Old-gen console and 3DS versions, falling blocks will not pass through.
Inactive Biome blocks will still count towards the formation of their respective biomes. This includes evil blocks.
Naturally occurring Lihzahrd Bricks cannot be actuated until Plantera has been defeated.
- This was originally possible by intention, because Biome Keys previously did not drop directly and required a Temple Key to craft. This was changed in 1.3.0.1 to remove the Biome Key Mold items, and in turn the need to consume Temple Keys.
NPCs can spawn on top of actuated blocks and thus fall through them.
Inactive blocks do not count as walls for NPC housing, so a house with actuated blocks making up any of its walls will become invalid.
The portals from the Portal Gun(Desktop, Console and Mobile versions), if placed before the blocks are actuated, will not vanish and will still function normally.
Actuators have no effect on blocks that one can already freely pass through, such as Bubble and variants of Living Fire Blocks.

Tips

Using Actuators in place of doors creates entrances that can completely block off the enemies from a Blood Moon or other events.
- It is also possible to make an airlock-type double door system using 6 Actuators and activating only one side inactive/active. This, combined with any trigger, will allow access for players only while keeping a house.
Because they work on traps, it is possible to load up several traps in a row, and none of their attacks will be blocked by traps ahead.
Actuators can be used to pass through Hellstone in the Underworld without generating lava, Chlorophyte without defeating the three Mechanical Bosses, and can similarly be used to pass through hive blocks without generating honey or spawning bees. The Actuation Rod may be used to quickly activate placed Actuators.
If the player stands inside an inactive block and it becomes active, the player can move inside the 6 blocks they are in, but will be stopped by other blocks. This may be used for protection.
(Desktop, Console and Mobile versions) Like naturally-generated wires, naturally-generated Actuators can be harvested, though they appear much more rarely, saving 10 SC per Actuator.
Actuators are a good tool for terraforming/clearing the way for a plot, especially underground.
Actuators can be removed from a block after setting it to an inactive state, the block will remain inactive even after the Actuator is removed and cannot be changed back to active unless actuated again.

Trivia

The Multicolor Wrench is not capable of removing Actuators, even though it is crafted using the Wire Cutter, which does remove Actuators.
- However, The Grand Design, crafted from the Multicolor Wrench, is capable of doing so.