Xenic Poltergeist

{T}: Until your next upkeep, target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

That Which Was Taken

{4}, {T}: Put a divinity counter on target permanent other than That Which Was Taken.
Each permanent with a divinity counter on it has indestructible.

Guardian Beast

As long as Guardian Beast is untapped, noncreature artifacts you control can't be enchanted, they have indestructible, and other players can't gain control of them. This effect doesn't remove Auras already attached to those artifacts.

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Shield of Kaldra

Equipment named Sword of Kaldra, Shield of Kaldra, and Helm of Kaldra have indestructible.
Equipped creature has indestructible. (Damage and effects that say "destroy" don't destroy it.)
Equip {4}

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)