Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Loyal Apprentice

Haste
Lieutenant — At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.

Gold Myr

Great Furnace

Ornithopter of Paradise

Sol Ring

Palladium Myr

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Ancient Den

Plains

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Losheel, Clockwork Scholar

Prevent all combat damage that would be dealt to attacking artifact creatures you control.
Whenever one or more artifact creatures you control enter, draw a card. This ability triggers only once each turn.

Mountain

Wake the Past

Return all artifact cards from your graveyard to the battlefield. They gain haste until end of turn.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Rustvale Bridge

Rustvale Bridge enters tapped.
Indestructible
{T}: Add {R} or {W}.

Iron Myr

Darksteel Citadel

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Gold-Forge Garrison

(Transforms from Golden Guardian.)
{T}: Add two mana of any one color.
{4}, {T}: Create a 4/4 colorless Golem artifact creature token.

Golden Guardian

Defender
{2}: Golden Guardian fights another target creature you control. When Golden Guardian dies this turn, return it to the battlefield transformed under your control.

Golden Guardian // Gold-Forge Garrison

Arcane Signet

Boros Signet

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Alibou, Ancient Witness

Other artifact creatures you control have haste.
Whenever one or more artifact creatures you control attack, Alibou, Ancient Witness deals X damage to any target and you scry X, where X is the number of tapped artifacts you control.

Lodestone Myr

Trample
Tap an untapped artifact you control: Lodestone Myr gets +1/+1 until end of turn.