Activate any number of mana-producing artifacts you control by tapping them, adding at least {R}{R}.
Activate Krark-Clan Ironworks by sacrificing any artifact except itself, adding {C}{C}.
Repeat step 2 for each remaining applicable artifact.
Activate Krark-Clan Ironworks by sacrificing itself, adding {C}{C}.
Cast Scrap Mastery by paying {3}{R}{R}, causing each player to exile all artifact cards from your graveyard, then sacrifice all artifacts they control, then return all exiled cards from exile to the battlefield.
Repeat steps 1-4 one additional time.
Activate Codex Shredder's second ability by paying {5}, tapping and sacrificing it, returning Scrap Mastery from your graveyard to your hand.
Repeat from step 5.
If artifacts you control can tap to produce at least {1}{R}{R}, this combo nets infinite mana of those types.
If you control four or more other nontoken artifacts as this combo begins, this combo nets infinite colorless mana.

Infinite colorless mana

Infinite magecraft triggers

Infinite mana artifacts you control can produce

Infinite storm count

Scrap Mastery

Codex Shredder

Krark-Clan Ironworks

Activate Time Sieve by tapping it and sacrificing it and four other nontoken artifacts except Codex Shredder, causing you to take an extra turn after this one.
Activate Codex Shredder's second ability by paying {5}, tapping and sacrificing it, returning Scrap Mastery from your graveyard to your hand.
Cast Scrap Mastery by paying {3}{R}{R}, exiling all artifact cards from all graveyards, then causing each player to sacrifice all artifacts they control and return all artifacts exiled this way to the battlefield under their owner's control.
Repeat each turn.

Infinite turns

Lock

Time Sieve

Cast Scrap Mastery by paying {3}{R}{R}.
In response, cast Dualcaster Mage by paying {1}{R}{R}.
Dualcaster Mage enters the battlefield, copying Scrap Mastery.
Activate Altar of Dementia by sacrificing Dualcaster Mage, causing any player to mill two cards.
Resolve a copy of Scrap Mastery, swapping all nonland permanents you control with all nonland permanents in your graveyard.
Repeat from step 3.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite mill

Infinite sacrifice triggers

Infinite self-mill

Infinite blinking of nonland permanents and nonland permanent cards in graveyard and in library

Encroaching Mycosynth

Dualcaster Mage

Altar of Dementia

Cast Scrap Mastery by paying {3}{R}{R}, swapping all nonland permanents you control for all nonland permanents in your graveyard.
Archaeomancer enters the battlefield, returning Scrap Mastery from your graveyard to your hand.
Activate Phyrexian Altar five times by sacrificing Archaeomancer and four other creatures, adding {R}{R}{R}{R}{R}.
Repeat.

Infinite colored mana

Archaeomancer

Phyrexian Altar

Combos with "Scrap Mastery"