[Source]
| “ | Pins Bloons in place for a short time when struck. | ” |
| ~ In-game description |
Pin is the 2nd upgrade of Path 3 for the Engineer Monkey in Bloons TD 6. It allows the Engineer to pin down all single-HP bloons for 1s, equivalent to a stun except affected bloons are struck by multiple nails attached. Pinned bloons are temporarily immobilized, and the status effect pins up to one layer, although an Engineer with this upgrade repeatedly attacking the same bloon will simply refresh the effect. Regardless of further upgrades or external buffs, this status effect cannot stop Lead, Ceramic Bloons, or Test Bloons, as these bloon types are unaffected by it.
Sentries with at least Sprockets will be able to inherit properties of the Pin effect. Cleansing Foam with Pin will briefly slow down all non-blimp Bloon types by 50%.
This upgrade costs $185 on Easy, $220 on Medium, $235 on Hard, and $265 on Impoppable.
Description
Overview
Engineers with Pin sport an all-black cap, a bulkier nail gun with a significantly thicker gray barrel, and a pair of orange work gloves with a black back.
The nail gun and gloves remain on all crosspaths, whereas the cap does not.
Pin adds the 
Pinned status effect onto affected bloons. The Engineer attacks every 0.70s and has 8 pierce. Pin also provides crosspathing effects to higher-tier sentries and foam.
Targeting Priorities
Pin targets bloons using the standard targeting priorities. Its main attack shoots straight movement projectiles.
- First: Targets the first bloon visible within its range.
- Last: Targets the last bloon visible within its range.
- Close: Targets the closest bloon visible within its range.
- Strong: Targets the strongest bloon visible within its range.
Costs
- Updated as of Version 46.0. Listed prices exclude external buffs, any sacrifices, and Monkey Knowledge.
| [Module | Data] | Purchase | Sell | ||||||
|---|---|---|---|---|---|---|---|---|
| Costs | Easy | Medium | Hard | Impoppable | Easy | Medium | Hard | Impoppable |
| Upgrade (X-X-2) | $185 | $220 | $235 | $265 | - | |||
| Total (0-0-2) | $860 | $1,020 | $1,100 | $1,225 | $602 | $714 | $770 | $858 |
| Crosspath (1-0-2) | $1,285 | $1,520 | $1,640 | $1,825 | $900 | $1,064 | $1,148 | $1,278 |
| Crosspath (2-0-2) | $1,625 | $1,920 | $2,070 | $2,305 | $1,138 | $1,344 | $1,449 | $1,614 |
| Crosspath (0-1-2) | $1,070 | $1,270 | $1,370 | $1,525 | $749 | $889 | $959 | $1,068 |
| Crosspath (0-2-2) | $1,365 | $1,620 | $1,750 | $1,945 | $956 | $1,134 | $1,225 | $1,362 |
This upgrade's prices (or included crosspath's prices) are affected by the following MK: 
Better Sell Deals
Strategy
Summary
Pin is a valuable upgrade for early-game stalling. Combined with the Oversize Nails' pierce bonus, it makes the Engineer become quite strong along straightaways. It also is pretty cheap, making it a very good option for the early game. It also serves as a great crosspath for a variety of Engineer upgrades.
Tips
- When further upgraded to Double Gun, it become quite useful against normal bloons.
- It is less useful after Round 81, as Super Ceramics are generally the only non-MOAB-class bloons that will appear on those rounds.
- Because this upgrade inherits extra pierce from the previous Oversize Nails upgrade, similar placements should be used for the Pin upgrade. In particular, even if the Double Gun upgrade is not purchased, the Engineer should still attack along straight lines for optimal effect.
- The Overclock upgrade gives the Engineer a massive pierce boost, which may make the 0-4-2 crosspath a good option for applying much more pin effects to excel in the mid-game.
- The pin effect actually prioritizes before the damage, so giving an Engineer with more damage through external buffs will actually prevent the pin effect from occurring.
- It may seem to be very similar to the Ice Monkey's freeze effect, but the major difference between the two is that Pin allows Sharp attacks to pop the pinned bloons, while freeze without Embrittlement won't allow them to deal damage.
Version History
Balance Changes
There is a very small buff specific to the Pin upgrade that affects crosspathing benefits.
- 26.0
| “ | [...] Additionally higher tier sentries will now be able to benefit from the xx2 Pin crosspath, so enjoy some laser pins. [...] | ” |
| ~ Ninja Kiwi |
3-0-2 Sentries & Higher will now also be able to Pin Bloons they pop
- 31.0
| “ | [...] Cleansing Foam has had some extra crosspath utility added at the cost of a small price increase and [...] | ” |
| ~ Ninja Kiwi, referring to Cleansing Foam crosspathing |
- Pin allows Cleansing Foam to slow Bloons 50% briefly. Due to a bug, this also includes all types of MOAB-Class Bloons, including BADs.
- 31.1
| “ | 032 Engineer Cleansing Foam now works correctly on all MOAB Class targets - hope you enjoyed that temporary treat | ” |
| ~ Ninja Kiwi, cheekily referring to the MOAB-class slowdown bug |
0-3-2 Cleansing Foam no longer slows MOAB-class bloons
Bug Fixes and General Changes
 |
This section is incomplete. You can help by expanding it. |
Extra Notes (Version History)
Gallery
Official artwork
Videos
Trivia
- Pin is tied with IFR from Heli Pilot for the shortest upgrade name in the whole BTD6 franchise in terms of character length.
- An Engineer Monkey with Pin nearby a Monkey Intelligence Bureau will still be unable to pin Leads or Ceramics. This is because the Monkey Intelligence Bureau purely changes all damage types for nearby towers to Normal. Since the Pin status effect is not identified as an attack, it does not gain the ability to affect all bloon types.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||