Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Survivors' Encampment

{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Dermotaxi

Imprint — As Dermotaxi enters, exile a creature card from a graveyard.
Tap two untapped creatures you control: Until end of turn, Dermotaxi becomes a copy of the exiled card, except it's a Vehicle artifact in addition to its other types.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Hollow Warrior

Hollow Warrior can't attack or block unless you tap an untapped creature you control not declared as an attacking or blocking creature this combat. (This cost is paid as attackers or blockers are declared.)

Liquimetal Coating

{T}: Target permanent becomes an artifact in addition to its other types until end of turn.

Ornithopter of Paradise

King Macar, the Gold-Cursed

Inspired — Whenever King Macar, the Gold-Cursed becomes untapped, you may exile target creature. If you do, create a Gold token. (It's an artifact with "Sacrifice this artifact: Add one mana of any color.")

Koskun Falls

At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.