Welding Jar

Sacrifice this artifact: Regenerate target artifact.

Demonic Junker

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When this Vehicle enters, for each player, destroy up to one target creature that player controls. If a creature you controlled was destroyed this way, put two +1/+1 counters on this Vehicle.
Crew 2

Island

Darksteel Citadel

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, draw two cards.

Simulacrum Synthesizer

When this artifact enters, scry 2.
Whenever another artifact you control with mana value 3 or greater enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Spire of Industry

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only if you control an artifact.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Frogmite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Mistvault Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {B}.

Aether Spellbomb

{U}, Sacrifice this artifact: Return target creature to its owner's hand.
{1}, Sacrifice this artifact: Draw a card.

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Tezzeret, Master of the Bridge

Creature and planeswalker spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)
+2: Tezzeret deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
−3: Return target artifact card from your graveyard to your hand.
−8: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.

Reality Heist

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Look at the top seven cards of your library. You may reveal up to two artifact cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.

Myr Enforcer

Portal to Phyrexia

When this artifact enters, each opponent sacrifices three creatures of their choice.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control. It's a Phyrexian in addition to its other types.

Mishra's Bauble

{T}, Sacrifice this artifact: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.