Plumbing
Pipe Small 1x1 Green
While not as sturdy as solid concrete, iron constructions have high structural integrity, requiring fewer support pillars.
Drops when destroyed
Iron× 1-2
Short Iron Pipe× 1
Where to find (2 POIs)
Vanity Tower (tier 5), Fort Camo (tier 4).
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.