Massive nails pop 8 bloons at once, and Frozen Bloons.
~ BTD6 description

Oversize Nails is the 1st upgrade of Path 3 for the Engineer Monkey in BTD6. It corresponds to the 9-Inch Nails upgrade from the BTD5 generation. It increases the pierce of the main Engineer's nailgun nails from 3 to 8, and allows them to pop Frozen Bloons. Unlike BTD5, this upgrade now also affects Sentry Guns, which now improves the Engineer's sentries to have +1 pierce and can pop Frozen Bloons.

It costs $380 on Easy, $450 on Medium, $485 on Hard, and $540 on Impoppable.


  • It makes useful early-game pierce akin to a Spike-O-Pult with greater attack speed but with significantly less pierce.
  • When further upgraded along Path 3, particularly with Double Gun, it is quite reliable at stalling early-game bloons.
    • This makes it the best early game Engineer Monkey.
  • Oversized Nails is one of the few sharp projectile towers that can pair well with Ice Shards for the activation of multiple ice shards.

Version History (BTD6)Edit


Buff Oversize Nails now adds +1 pierce to all sentries deployed by the Engineer



  • It is not known why "Oversized Nails" no longer used the name "9-Inch Nails".
  • The upgrade icon for Oversize Nails is a frozen Red Bloon penetrated by three nails.
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