Doors and hatches
Blue Steel Garage Door 5x3
Press & hold Activate to lock it or set a combination. Upgrade & repair with a construction tool using the secondary action.
Harvest drops
Iron× 750
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
Drops when destroyed
Spring× 8-12
Mechanical Parts× 8-12
When it collapses
Falling, it leaves 
Wood Debris (Terrain) (75% of the time) where it lands.
Where to find (2 POIs)
NC Bus Repair Site (tier 2), Dirty Laundry (tier 1).
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.