Your situation

Day one, a pile of scrap

Level Crafting to 2 and make Wire, Plastic Sheet, Wooden Plank, Container, Cardboard. Each is 3 of one scrap, none can fail, and every furniture package you will want later asks for them. Do not touch the metal chain yet: Fine Sheet Metal, Tempered Glass, Iron Parts, Iron Rod need Crafting 4 or more, and Iron Parts also waits on a talent (Hydroponic Cultivation); Iron Rod also waits on a talent (Indoor Sunlight, Hydroponic Cultivation, A Good Bed, Post-Work Relaxation, Hot Bath).

A recipe I cannot see

Open the crafting list and read its unlock line. A talent recipe needs that talent bought; an event recipe appears when the event fires; a Defense recipe waits on the Defense skill. Poor-Quality Molotov Cocktail is the one most players ask about: Defense level 2, not a Crafting level. Rescue Beacon needs its blueprints in hand as well as the scrap.

A recipe that keeps failing

Only 7 recipes can fail: Fortification Reinforcement Components, Rescue Beacon, Door Repair Kit, Window Repair Kit, All-Purpose Strengthener, Fine Sheet Metal, Iron Animal Trap. A failure hands part of the materials back and keeps the rest: Fortification Reinforcement Components loses nothing; Rescue Beacon loses Broken Glass, Waste Plastic, Scrap Metal; Door Repair Kit loses nothing; Window Repair Kit loses nothing; All-Purpose Strengthener loses nothing; Fine Sheet Metal loses Scrap Metal ×2; Iron Animal Trap loses Waste Plastic, Scrap Metal. The fail chance is not printed anywhere in the game’s data, so this site does not state one; the perfect-craft chance is, and Crafting 2 adds to it.

Open the crafting list All the recipes under the Workbench's own tabs, with materials, scrap from scratch, level, unlock and what a failure returns.

The Workbench has 128 recipes under 7 tabs, and the tabs are the best map of what it is for: Raw Materials (16), Tools & Equipment (5), Trapping/Hunting (8), Gardening (18), Electrical Power (11), Defenses (16), Furniture (54). Most of them make a furniture package you then install, which is why the list is the other half of the equipment list.

The parts everything is made of

What the Workbench makes out of scrap, and how many recipes each part goes into.
Part Made from Crafting level Used in Can fail
Wire Scrap Metal ×3 2 36 no
Plastic Sheet Waste Plastic ×3 2 22 no
Wooden Plank Wood Chips ×3 2 15 no
Fine Sheet Metal Scrap Metal ×4 4 13 yes
Tempered Glass Broken Glass ×4 4 12 no
Container Broken Glass ×3 2 10 no
Iron Parts Iron Rod ×2 4 9 no
Cardboard Scrap Paper ×3 2 7 no
Iron Rod Fine Sheet Metal ×2 4 6 no

Two chains sit in that table. The basics are one scrap each, three units to a part, at Crafting 2, and nothing but the level gates them. The metal chain is longer, and Iron Parts and Iron Rod appear only once one of the talents that names them is bought, whatever your level: Fine Sheet Metal from Scrap Metal ×4; Tempered Glass from Broken Glass ×4; Iron Parts from Iron Rod ×2; Iron Rod from Fine Sheet Metal ×2. Follow it back and one Iron Parts Materials 2000 g 2×3 cells Keeps indefinitely "Always wanted to get into handicrafts. Now I've got all the time in the world..." costs Scrap Metal ×16, which is what the Extra Large generator and cage are really asking for.

Where the scrap comes from

The base materials no recipe makes, and every way the game hands them over.
Material How you get it Recipes that want it
Abandoned Drone searched, salvaged from furniture 1
Bandage searched, stocked by the stranger 1
Broken Glass searched, bought, traded for, given, stocked by the stranger, salvaged from furniture 25
Common Alcohol bought, given 2
Electronic Components searched, bought, given, stocked by the stranger, salvaged from furniture 34
High-Proof Alcohol searched, given 2
Poor-Quality Alcohol given 2
Rescue Beacon Blueprints given, salvaged from furniture 1
Scrap Metal searched, bought, traded for, caught, given, stocked by the stranger, salvaged from furniture 69
Scrap Paper searched, bought, traded for, given, salvaged from furniture 16
Waste Plastic searched, bought, traded for, given, stocked by the stranger, salvaged from furniture 28
Wood Chips searched, bought, traded for, given, salvaged from furniture 18

Salvage is the entry most players miss: dismantling furniture returns scrap, so a house full of furniture you do not use is a scrap store. The supplies list shows, for any material, which furniture salvages into it and which shelves stock it.

What hands you a recipe

How many recipes each kind of source opens. A recipe can have more than one.
Source Recipes
On the bench from the start, at its Crafting level 34
A talent 50
An event in the run 36
A story item 4
A Defense level 7
The start of Endless mode 29

The Defense list is short and specific: level 2 opens Poor-Quality Molotov Cocktail and Molotov Cocktail and High-Proof Molotov Cocktail; level 3 opens Electric Trap Package; level 4 opens Mechanical Chainsaw Package; level 5 opens Titanium Door Package and Bulletproof Window Package. One line in the game disagrees with its own tables: the Defense 1 rank text says "Can craft Sandbag and Spike Barrier", but the tables put no recipe behind that level, and Sandbag Package and Spike Barrier Package sit on the bench with no level and no unlock. Expect to see them from the start. What raises Defense itself is on the skills list.

Brewing and the shredder

Two of the event recipes are stations of their own. The Brewing Barrel Package (Scrap Metal ×5, Broken Glass ×4, Waste Plastic ×2) arrives with the event "Set Up Brewing Barrel", and the Shredder Package (Wooden Plank ×3, Wire ×2, Fine Sheet Metal ×2, Plastic Sheet, Electronic Components) with "Assemble a Shredder". Both are furniture packages; what each does once installed is on the equipment list.

What to do

  1. Reach Crafting 2 before anything else on the bench; it opens the basic parts.
  2. Keep every scrap you find. 12 base materials feed all 128 recipes.
  3. Salvage furniture you do not use rather than leaving it standing.
  4. Before you level Crafting for a recipe you cannot see, check its unlock in the crafting list. Most locked recipes wait on a talent or an event, not a level.
  5. Make the metal chain only once you have a generator or cage worth the scrap it eats. What a supply is worth has what an item is worth as an input against what it is worth sold.

Quick reference

  • Recipes: 128, under 7 tabs.
  • Basic parts: Wire, Plastic Sheet, Wooden Plank, Container, Cardboard, at Crafting 2.
  • Metal chain: Scrap Metal → Fine Sheet Metal → Iron Rod → Iron Parts.
  • Can fail: Fortification Reinforcement Components, Rescue Beacon, Door Repair Kit, Window Repair Kit, All-Purpose Strengthener, Fine Sheet Metal, Iron Animal Trap.
  • Unlocks: 50 by talent, 36 by event, 7 by Defense.