Plumbing
Pipe Small 1x1 Yellow
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 (6 POIs)
Hybrid Mining (tier 5), Pipeline Gas Co (tier 4), Eye Candy Company, PGC Compressor Station #4, PGC Compressor Station #5, PGC Compressor Station #7.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.