The sheet metal wall has a weak side which is marked by diagonal bars. The edge areas of the wall are as strong as the front.

• 10x Tools
  
• 10x Melee weapons
  
• 2x Bullets
  
• 2x Slugs
  
• 1.05x Explosive Bullets
  
• 1x Explosives

• Timed Explosive Charge: 275dmg (4 charges)
  
• Rocket Launcher(Rocket): 137dmg (*) (8 rockets)
  
• Satchel Charge: 58dmg (18 charges)
  
• Rocket Launcher(High Velocity Rocket): 31dmg (*) (33 rockets)
  
• Landmine: 18dmg (*)(~) (56 mines)
  
• 40mm HE Grenade: 17dmg (*) (59 grenades)
  
• Beancan Grenade(right click): 12dmg (!) (84 grenade)
  
• Beancan Grenade(left click): 10dmg (*)(!) (100 grenades)
  
• Survey Charge: 5.5dmg (*) (182 charges)
  
• F1 Grenade(right click): 1dmg (1000 grenades)
  
• F1 Grenade(left click): 0.09dmg (*) (11,112 grenades)
  
• Rocket Launcher(Incendiary Rocket): 0dmg (#)

* Inflicts splash damage to building parts.
! Can explode a moment after placing/throwing them.
~ Tool cupboards can block placement.
# Causes a horrific amount of fire that spreads, although sheet metal walls are immune to fire damage.

Explosive notes:
F1 grenades are better suited for anti-personnel use rather than demolition. Incendiary rockets have no effect on sheet metal walls.

• Longsword: 0.07dmg (1,588 swords) 9 hits per weapon
  
• Stone Spear: 0.05dmg (2,000 spears) 10 hits per weapon
  
• Salvaged Cleaver: 0.05dmg (1,539 cleavers) 13 hits per weapon
  
• Wooden Spear: 0.05dmg (1,053 spears) 19 hits per weapon
  
• Mace: 0.05dmg (1,539 maces) 13 hits per weapon
  
• Salvaged Sword: 0.047dmg (819 swords) 26 hits per weapon
  
• Machete: 0.033dmg (2,332 machetes) 13 hits per weapon
  
• Bone Knife: 0.02 dmg (2,000 knives) 25 hits per weapon
  
• Bone Club: 0.011dmg (3,953 clubs) 23 hits per weapon

• Salvaged Icepick: 0.06dmg (278 pickaxes) 60 hits per tool
  
• Pickaxe: 0.04dmg (439 pickaxes) 57 hits per tool
  
• Salvaged Axe: 0.033dmg (506 axes) 60 hits per tool
  
• Jackhammer: 0.029dmg (466 jackhammers) 74 hits per tool
  
• Stone Pickaxe: 0.025dmg (1,819 pickaxes) 22 hits per tool
  
• Salvaged Hammer: 0.025dmg (572 hammers) 70 hits per tool
  
• Hatchet: 0.025dmg (607 hatchets) 66 hits per tool
  
• Stone Hatchet: 0.014dmg (2,748 hatchet) 26 hits per tool
  
• Rock: 0.009dmg (3,473 rocks) 32 hits per tool
  
• Torch: 0.004dmg (11,364 torches) 22 hits per tool
  
• Torch(lit): 0.004dmg (41,667 torches) 6 hits per tool

• Waterpipe Shotgun: 0.0?dmg
  
• Eoka Pistol: 0.0?dmg
  
• Double Barrel Shotgun: 0.0?dmg
  
• Pump Action Shotgun: 0.0?dmg
  
• Spas-12: 0.0dmg

Notes:
Handmade shells inflict negligible damage to sheet metal walls.

• Waterpipe Shotgun: 0.0?dmg
  
• Eoka Pistol: 0.0?dmg
  
• Double Barrel Shotgun: 0.0?dmg
  
• Pump Action Shotgun: 0.0?dmg
  
• Spas-12: 0dmg

Notes:
Buckshot shells inflict negligible damage to sheet metal walls.

• Waterpipe Shotgun: 0.125dmg (8,000 slugs)
  
• Eoka Pistol: 0.125dmg (8,000 slugs)
  
• Double Barrel Shotgun: 0.125dmg (8,000 slugs)
  
• Pump Action Shotgun: 0.125dmg (8,000 slugs)
  
• Spas-12: 0dmg

• Double Barrel Shotgun: 0dmg
  
• Eoka Pistol: 0dmg
  
• Pump Action Shotgun: 0dmg
  
• Spas-12: 0dmg
  
• Waterpipe Shotgun: 0dmg

• Grenade Launcher: 0.00125dmg (80,000 shells)

• Bolt Action Rifle: 0.0039dmg (256,411 rounds)
  
• M249: 0.0032dmg (312,500 rounds)
  
• Assault Rifle: 0.0025dmg (400,000 rounds)
  
• LR-300: 0.002dmg (500,000 rounds)
  
• Semi-Automatic Rifle: 0.002dmg (500,000 rounds)

• Bolt Action Rifle: 2.4dmg (417 rounds)
  
• Assault Rifle: 2.4dmg (417 rounds)
  
• LR-300 Assault Rifle: 2.4dmg (417 rounds)
  
• M249: 2.4dmg (417 rounds)
  
• Semi-Automatic Rifle: 2.4dmg (417 rounds)

Notes:
Explosive rounds inflict almost the same damage to the weak side as the strong side of walls at 1.05x, and can start fires, but the fire inflicts no damage to sheet metal walls.

• Bolt Action Rifle: 0.0?dmg
  
• M249: 0.0?dmg
  
• Assault Rifle: 0.0?dmg
  
• LR-300: 0.0?dmg
  
• Semi-Automatic Rifle: 0.0?dmg

Notes:
Incendiary rifle ammunition can start fires, but the shots inflict negligible damage to sheet metal walls, and the fire inflicts no damage to sheet metal walls.

• Python Revolver: ~0.0017dmg
  
• MP5: 0.0017dmg (588,236 rounds)
  
• Thompson: ~0.0017dmg
  
• Semi-Automatic Pistol: ~0.0017dmg
  
• Custom SMG: ~0.0017dmg
  
• Revolver: ~0.0017dmg
  
• M92: ~0.0017dmg

Notes:
I only bothered testing the MP5.

• Python Revolver: 0.0?dmg
  
• MP5: 0.0?dmg
  
• Thompson: 0.0?dmg
  
• Semi-Automatic Pistol: 0.0?dmg
  
• Custom SMG: 0.0?dmg
  
• Revolver: 0.0?dmg
  
• M92: 0.0?dmg

Notes:
Incendiary pistol bullets can start fires, but the shots inflict negligible damage to sheet metal walls, and the fire inflicts no damage to sheet metal walls.

• Bow(Bone Arrow): 0dmg
  
• Bow(Fire Arrow): 0dmg
  
• Bow(High Velocity Arrow): 0dmg
  
• Bow(Wooden Arrow): 0dmg
  
• Crossbow(Bone Arrow): 0dmg
  
• Crossbow(Fire Arrow): 0dmg
  
• Crossbow(High Velocity Arrow): 0dmg
  
• Crossbow(Wooden Arrow): 0dmg
  
• Nailgun(Nailgun Nails): 0dmg

• Chainsaw: 0dmg
  
• Flamethrower: 0dmg
  
• Molotov: 0dmg

Notes:
As low as 13 fuel can start a fire, but fire has no effect on sheet metal walls.

The sheet metal foundation has strong vertical faces, and a weak flat face showing treadplate. It's otherwise the same as the sheet metal wall.

The sheet metal doorway is exactly the same as the sheet metal wall, but costs 45 metal fragments less to upgrade.

The sheet metal window building part is exactly the same as the sheet metal wall, but costs 45 metal fragments less to upgrade.

The sheet metal floor has a strong face on the walking side, and a weak face on the side you'd bump your head on. It's otherwise the same as the sheet metal wall.

With Rust being consistently updated I haven't had the time to keep up. Some of the information may be out of date, and misses newer weapons.