Enthusiastic Mechanaut

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

Scrap Trawler

Whenever Scrap Trawler or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Tidy Conclusion

Destroy target creature. You gain 1 life for each artifact you control.

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever Kappa Cannoneer or another artifact you control enters, put a +1/+1 counter on Kappa Cannoneer and it can't be blocked this turn.

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Chandra, Flame's Catalyst

+1: Chandra, Flame's Catalyst deals 3 damage to each opponent.
−2: You may cast target red instant or sorcery card from your graveyard. If that spell would be put into your graveyard, exile it instead.
−8: Discard your hand, then draw seven cards. Until end of turn, you may cast spells from your hand without paying their mana costs.

Davros, Dalek Creator

Menace
At the beginning of your end step, create a 3/3 black Dalek artifact creature token with menace if an opponent lost 3 or more life this turn. Then each opponent who lost 3 or more life this turn faces a villainous choice — You draw a card, or that player discards a card.

Vedalken Engineer

{T}: Add two mana of any one color. Spend this mana only to cast artifact spells or activate abilities of artifacts.

Reckless Fireweaver

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Knight Paladin

Trample
Rapid-fire Battle Cannon — When Knight Paladin enters, it deals 4 damage to each opponent.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Steel Overseer

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

Foundry Inspector

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

Disentomb

Return target creature card from your graveyard to your hand.

Vedalken Humiliator

Metalcraft — Whenever Vedalken Humiliator attacks, if you control three or more artifacts, creatures your opponents control lose all abilities and have base power and toughness 1/1 until end of turn.

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Research Thief

Flash
Flying
Whenever an artifact creature you control deals combat damage to a player, draw a card.

Master Transmuter

{U}, {T}, Return an artifact you control to its owner's hand: You may put an artifact card from your hand onto the battlefield.

Sygg, River Cutthroat

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Sculpting Steel

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