Killing Floor 3: All Crafting Materials & Where to Farm Them (drop sources & map tips)

From Kiosks to Bosses: Where Every Crafting Material Drops in KF3

This guide lists every crafting material in KF3, what it’s used for, where it drops (Zeds & destructibles), and the fastest places + routes to farm each one.

How the materials economy works (fast primer)

• The 8 materials & what they’re for.
  • Bio Sample → Ammo pouches, grips, magazines. Drops from Gorefasts, Husks, Sirens (codex also lists Kiosk/Satcom; see note below).
  • Bio Steel (aka Biosteel) → Barrels, blades, pommels, receivers, sights. Drops from Gorefasts, Husks, Sirens, and Kiosk/Satcom destructibles.
  • Chemical Agent → Ammos, coatings, underbarrel attachments. Drops from Cysts, Clots, Crawlers.
  • Electrical Parts → Barrels, receivers, sights. Drops from Clots, Gorefasts; also from Cameras, Loudspeakers, and Power Walls.
  • Gray Matter → High‑value ammo & attachment mods (ammo, coatings, grips, mags, some underbarrels). Drops from Bloats, Husks, Sirens.
  • Scrap Metal → Blades, pommels, receivers. Drops from Clots & Gorefasts; also from Cameras/Loudspeakers/Power Walls.
  • Zed Tech → Required for all Tier 2 weapon‑mod upgrades; drops from Scrakes & Fleshpounds.
  • Ichor → Required for all Tier 3 weapon‑mod upgrades; drops from bosses (Impaler, Chimera, Queen Crawler).
• Destructibles = free mats, XP, and dosh. The five breakables are Kiosk, Satcom, Camera, Loudspeaker, Power Wall—and their presence varies by map (see cheat‑sheet below). Cameras/Loudspeakers/Power Walls drop Electrical Parts/Scrap Metal; Kiosk/Satcom drop Bio Steel (codex lists Bio Sample, but there’s an important caveat).
• Important Bio Sample caveat. Although the codex and several guides list Kiosk/Satcom as Bio Sample sources, Game8’s testing notes they currently don’t drop Bio Sample (likely a bug/very low chance). Treat Bio Sample as a Zed‑only farm until patched.
• “Die to bank” solo trick. Quitting the match won’t save destructible‑drop materials. If you’re speed‑farming props solo, let Zeds kill you to hit the results screen, then map‑vote back into the farm. This is specifically recommended in Electrical/Biosteel farm guides.
• Blueprints are unlocked; materials are the bottleneck. After launch, weapon mod blueprints are available in the Stronghold by default—you “just” need the materials.
• Recycling returns 66% of invested materials. If you crafted a bad roll, recycling a mod gives two‑thirds of the mats back.
• Team loot quirks. Community testing suggests environmental mats (props) are shared, but Zed‑kill mats are personal. Don’t rely on teammates to feed you Zed drops; rotate kills fairly.

Map cheat‑sheet: where each destructible actually spawns

Use this to pick the right battlefield for your shopping list.

• Kiosk → R&D Lab, City Streets, Horzine Factory, Offices (great for Bio Steel).
• Satcom → Army Depot, Radar Station, Sewers (also Bio Steel now; watch the Bio Sample caveat).
• Camera → Army Depot, R&D Lab, City Streets, Radar Station, Horzine Factory, Convoy, Offices (Electrical Parts/Scrap Metal).
• Loudspeaker → Army Depot, City Streets, Radar Station, Horzine Factory, Convoy, Offices, Sewers (Electrical Parts/Scrap Metal).
• Power Wall → R&D Lab, Horzine Factory, Offices, Sewers (Electrical Parts/Scrap Metal).

Fastest farms & best routes (by material)

Below you’ll find a condensed “what it’s for → who drops it → where to farm it” with a practical route where applicable.

1) Bio Steel (Biosteel) — Barrels, Blades, Pommel, Receiver, Sights

Drops: Husks, Sirens, Gorefasts; Kiosk/Satcom destructibles.

Best farm: City Streets — 6‑Kiosk circuit

• Start at Rooftop Park spawn: two Kiosks are here (one at the top of the stairs; one by the bridge).
• Look out to the main street for Kiosk #3; follow the road to a building with two turrets for #4; turn down the alley inside for #5; push into Employee Residences hugging the left wall for #6.
• Let Zeds kill you to bank mats; map‑vote City Streets again and repeat.

Other solid maps: Any with Satcom lines—Army Depot, Radar Station, Sewers—if you’re bored of City Streets laps.

2) Electrical Parts — Barrels, Receivers, Sights

Drops: Clots, Gorefasts; Cameras, Loudspeakers, Power Walls.

Best farm: City Streets — Camera/Speaker loop

• This map has dense placements of Cameras and Speakers, and a very clean loop.
• Run a clockwise street lap on Solo, pop every camera/speaker you see, die to bank, then rematch. It’s the most brain‑off Electrical farm.

Backup maps: Horzine Factory and Offices (lots of Cameras + Power Walls), Convoy (Cameras/Speakers in sightlines). Use the destructibles table above to pick.

3) Scrap Metal — Blades, Pommels, Receivers

Drops: Clots, Gorefasts; Cameras, Loudspeakers, Power Walls.

Best farm: Any map rich in Cameras/Speakers — again, City Streets shines for prop density (do the same loop as Electrical Parts). R&D Lab and Offices are also good for Power Walls.

Tip: If you’re also chasing Chemical Agent/Gray Matter, run the loop during Wave 2–3 then finish waves with your squad to stack both prop and Zed drops.

4) Chemical Agent — Ammos, Coatings, Underbarrels

Drops: Cysts, Clots, Crawlers (Zed only).

Best farm: Full lobbies on Normal/Hard

• Chemical Agent is a pure mob‑Zed material. The fastest way to get lots is simply playing co‑op so spawn counts scale up; look for open maps where you can keep waves grouped and melted.

Perks that help: Commando & Firebug delete trash waves quickly; Medic pistol tagging keeps you alive while you hoover drops.

5) Gray Matter — Ammo, Coatings, Grips, Mags, Underbarrels

Drops: Bloats, Husks, Sirens.

Best farm: Matchmake & farm elite spawns

• Gray Matter comes from “ranged/elites” like Husks/Sirens. Online play increases total spawns; run stable open holds and prioritize Husks/Sirens as they spawn.

Map ideas: Horzine Factory (clean lanes + Power Walls for backup scrap), Offices (predictable spawn funnels). Check your team’s comp so you can reliably snipe elites.

6) Bio Sample — Ammo pouches, Grips, Magazines

Drops: Gorefasts, Husks, Sirens; codex lists Kiosk/Satcom but see bug note.

Best farm: General play (full lobbies)

• Treat Bio Sample like Gray Matter: play co‑op for volume, hunt the same elites.
• If/when Kiosk/Satcom start reliably dropping Bio Sample (post‑patch), City Streets Kiosk circuit and Army Depot/Radar Station/Sewers Satcom routes will become top‑tier. For now, assume Zed‑only.

7) Zed Tech — All Tier 2 mod upgrades

Drops: Scrakes & Fleshpounds.

Best farm: Hard/Hell on Earth (spawn earlier & more frequently)

• Jump to Hard+ so Scrakes/Fleshpounds enter rotations sooner and more often. Bring a balanced team; you need to personally tag these targets to get the drop chance, per player reports.

Map ideas: Convoy (easy looping sightlines & sentry placements), Army Depot (predictable boss corridors). Focus fire to end rages quickly.

8) Ichor — All Tier 3 mod upgrades

Drops: Bosses—Impaler, Chimera, Queen Crawler.

Best farm: Spam Normal and complete matches

• Since Ichor only comes from bosses, the fastest efficient path is finishing matches on Normal with a full squad, then repeat. Destructoid’s testing notes bosses consistently drop Ichor (amount varies), so reliability beats difficulty here.

City Streets: the one farm every player should know

If you only remember one route, make it City Streets—it concentrates Kiosks (Bio Steel) plus tons of Cameras/Speakers (Electrical Parts/Scrap Metal):

1. Spawn at Rooftop Park if possible—grab the two Kiosks up top.
2. Drop to the main street for another Kiosk, then up the road to the turreted building (Kiosk #4).
3. Cut through the alley to the interior Kiosk #5, and finish at Employee Residences (#6).
4. Along the way, shoot every Camera/Speaker you see; they’re everywhere in City Streets.
5. Intentionally die to bank mats, map‑vote City Streets, repeat.

Map‑by‑map shopping list (quick reference)

• Army Depot — Cameras, Loudspeakers, Satcom → Electrical Parts/Scrap Metal + (Bio Steel via Satcom). Good for varied prop runs.
• City Streets — Cameras, Loudspeakers, Kiosks → Top farm for Electrical/ Scrap + Biosteel.
• R&D Lab — Cameras, Power Walls, Kiosks → Great for Electrical/Scrap and some Biosteel.
• Radar Station — Cameras, Loudspeakers, Satcom → Electrical/Scrap + Biosteel.
• Horzine Factory — Cameras, Loudspeakers, Power Walls, Kiosks → All three prop types; flexible farm.
• Convoy — Cameras, Loudspeakers → Clean sightlines for prop loops; pair with Zed Tech hunting on Hard+.
• Offices — Cameras, Loudspeakers, Power Walls, Kiosks → Versatile prop map with good funnels.
• Sewers — Loudspeakers, Power Walls, Satcom → No cameras, but rich in other props.

Power farming: 10 practical tips

1. Co‑op for Zed drops, Solo for prop laps. Zed drop volume scales with lobby size; prop routes are faster unopposed.
2. Always tag Scrakes/Fleshpounds (one bullet is enough) so you’re eligible for the Zed Tech drop chance.
3. Recycle bad rolls—a failed mod reroll still refunds ~66% of mats.
4. Blueprint sanity: don’t chase blueprint drops—they’re already unlocked in Stronghold; materials are your gate.
5. Banking solo mats: don’t quit → die on purpose after your lap to save mats.
6. Prioritize elites (Husks/Sirens/Bloats) if you need Gray Matter/Bio Sample; communicate kill‑priority in voice/pings.
7. Hold efficient positions with clear sightlines (Convoy/Offices/Factory) when farming Zed Tech so you can defang rages.
8. Remember loot rules: teammates share prop mats but not Zed mats (community observation)—rotate kills fairly.
9. Boss‑rush Ichor: queue Normal, run cleanly to the boss, repeat. Keep a dedicated reviver so wipes don’t waste runs.
10. Know your destructibles on each map; build mental routes.

Full material table (at a glance)

FAQ (quick hitters)

• Do bosses always drop Ichor? Player‑side testing reports consistent Ichor on boss kills, with variable amounts.
• What difficulty should I farm Zed Tech on? Hard (or higher) to spawn Scrakes/Fleshpounds earlier and more often—ideally in co‑op.
• What if I craft a mod with a bad Bonus Ability? Recycle and retry; expect ~33% loss per reroll attempt.