What's the use of accumulating junk? [duplicate]

Question

Can I use junk for any specific need? Can I assign junk items to a dweller?

Answer 1

Junk cannot be used in any dweller's equipment slots or associated with specific dwellers in any way. It can only be consumed at a workshop or sold.

Workshops

There are two types of workshops: the Weapon Workshop and the Outfit Workshop. You can craft items at these workshops. To create any particular item, you will first need to acquire its blueprint. The blueprint will specify how many of each type of junk are needed to create the item.

Blueprints and Junk

You can find blueprints in the wasteland. Sometimes raiders will drop them when killed in your vault. Blueprints can be common, rare or legendary. In order to create rare or legendary weapons and outfits, you will need to upgrade the relevant room.

You can find junk in the wasteland, or can break down weapons and outfits in your storage. Note that each piece of junk takes up space in your storage, so keeping all the junk can quickly lead to you running out of room. You can sell junk, just like outfits and weapons.

Craftable Items

You can craft things that you don't seem to be able to find in the wasteland, or at least you can craft things that none of my explorers have ever found.

Even without upgrades, you can craft useful things like Flight Suits (E+1, A+2) and Wasteland Gear (E+3) in the outfit workshop or things like Rusty Laser Pistols (7 Dmg) in the weapon workshop. With upgrades, you can craft powerful items like the MIRV (22‑27 Dmg) or the X-01 Mk VI Power Armor (S+5, P+1, E+1).

Answer 2

Junk can be used for crafting.

With the 1.4 update, two new rooms were added to Fallout Shelter;

• Weapon Workshop: allows you to create weapons from junk.
• Armour Workshop: allows you to create armor from junk.

You can also convert weapons and armor into junk, though it is not a guaranteed conversion.