Massive nails pop 8 bloons at once, and pop Frozen Bloons.
”
~ BTD6 description
Oversize Nails (BTD6) is the 1st upgrade of Path 3 for the Engineer Monkey in BTD6. It increases the pierce of the main Engineer's nailgun nails from 3 to 8, and allows them to pop Frozen Bloons. It costs $TBA on Easy, $450 on Medium, $485 on Hard, and $540 on Impoppable.
Tips
It makes useful early-game pierce akin to a Spike-O-Pult with nearly double attack speed but with nearly 1/3 pierce.
When further upgraded along Path 3, particularly with Double Gun, it is quite reliable at stalling early-game bloons.
Oversized Nails is one of the few sharp projectile towers that can pair well with Ice Shards for the activation of multiple ice shards.
Trivia
It is not known why "Oversized Nails" no longer used the name "9-Inch Nails", but the name was likely modified to avoid confusion between real-world distance units and in-game distance units, as well as the fact that it seemed a little awkward to add a band reference for an engineer.