Doors and hatches
Black Steel Garage Door 4x3
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 (3 POIs)
Shotgun Messiah Range (tier 4), Old Genrik Plant, Soakley Residence.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.