Grey Iron Hatch
Press & hold Activate to lock it or set a combination. Upgrade & repair with a construction tool using the secondary action.
Upgrade path
Hit a placed block with a stone axe, claw hammer or nail gun while carrying the material of the next step: 6 hits per upgrade.
Crafting
Craft at Backpack · makes 1
Crafted as Iron Hatch: pick this one of its variants when you place it.
Forged Iron× 10
Harvest drops
Iron× 20-30
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Scrap Metal Pile (75% of the time) where it lands.
Where to find (74 POIs)
7 Days Suites (tier 5), Area 7 (tier 5), Champions Coliseum (tier 5), Correa Rockworx (tier 5), Haven Hotel (tier 5), Hybrid Mining (tier 5), Minotaur Theater (tier 5), Navezgane Athletics Complex (tier 5), Navezgane Corrections (tier 5), Navezgane County Jail (tier 5), Red Mesa Compound (tier 5), Shamway Factory (tier 5), ChemTech Distribution Center (tier 4), Ironwood Paper Mill (tier 4), Joe's Junction (tier 4), Water Treatment Plant (tier 4), Church Of The Blinding Faith (tier 3), Fort Razor (tier 3), Meat You Here Butchery (tier 3), Navezgane Falls Diner (tier 3), Pop-N-Pills (tier 3), Soyer Family Farm (tier 3), The Bend Apartments (tier 3), Boar Barn Fields (tier 2), Booze Hound Brewery (tier 2), Mason's Barn (tier 2), McPherson UFO Museum (tier 2), Mo Power Components Factory (tier 2), Navezgane Creamery (tier 2), NFD Engine 4 (tier 2), Soyer Family Slaughterhouse (tier 2), The Jensen Residence (tier 2), z-work (tier 2), Bath Haus (tier 1), Bear-N-Land Coal Mining (tier 1), Bomb Shelter 41 (tier 1), Cabin Retreat (tier 1), Camp Carlson (tier 1), Navezgane Civil Defense Shelter (tier 1), Pass-N-Gas Store #04 (tier 1) and 34 more.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.