Ashnod's Altar

Dross Scorpion

Whenever Dross Scorpion or another artifact creature dies, you may untap target artifact.

Krark-Clan Ironworks

Golem Foundry

Whenever you cast an artifact spell, you may put a charge counter on Golem Foundry.
Remove three charge counters from Golem Foundry: Create a 3/3 colorless Golem artifact creature token.

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.

Traxos, Scourge of Kroog

Trample
Traxos, Scourge of Kroog enters tapped and doesn't untap during your untap step.
Whenever you cast a historic spell, untap Traxos. (Artifacts, legendaries, and Sagas are historic.)

Grinding Station

{T}, Sacrifice an artifact: Target player mills three cards.
Whenever an artifact enters, you may untap Grinding Station.

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Genesis Chamber

Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Razor Boomerang

Equipped creature has "{T}, Unattach Razor Boomerang: It deals 1 damage to any target. Return Razor Boomerang to its owner's hand."
Equip {2}

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Junk Diver

Flying
When Junk Diver dies, return another target artifact card from your graveyard to your hand.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.