What spells on the TCoE Artificer Spell List require a free hand when the Artificer holds an infused item in their hand?

Question

Considering the class feature Tools Required:

You must have a spellcasting focus—specifically thieves’ tools or some kind of artisan’s tool—in hand when you cast any spell with this Spellcasting feature (meaning the spell has an “M” component when you cast it). [..] After you gain the Infuse Item feature at 2nd level, you can also use any item bearing one of your infusions as a spellcasting focus.

and the complete guidance regarding components in the SAC, but mainly:

If a spell’s material components are consumed, can a spellcasting focus still be used in place of the consumed component? No. A spellcasting focus can be used in place of a material component only if that component has no cost noted in the spell’s description and if that component isn’t consumed.

What spells on the Artificer Spell List, TCoE, require the second class level or higher Artificer to have a free hand when they have access to an infused shield or weapon in one of their hands?

Answer 1

There's a fairly small number of Artificer spells with costly or consumed material components, and most of them are primarily useful outside of combat.

So it's probably not a problem to have to put down whatever you might normally have in your other hand for a while. Here's the list (with parenthetical notes for ones in which a free hand is probably not an issue very often):

• Booming Blade (the valuable component is a weapon, so probably fine in combat)
• Green-Flame (the valuable component is a weapon, so probably fine in combat)
• Identify (non-combat, casting time of 1 minute)
• Snare (non-combat, casting time of 1 minute)
• Arcane Lock (usually non-combat)
• Continual Flame (usually non-combat)
• Magic Mouth (non-combat, casting time of 1 minute)
• Glyph of Warding (non-combat, casting time of 1 hour)
• Revivify
• Leomund's Secret Chest (usually non-combat)
• Stoneskin
• Summon Construct
• Greater Restoration

Only four of the higher-level spells are both likely to be useful and somewhat awkward to cast in combat. Even those four are marginal, as you can often cast them outside of initiative. Stoneskin and Summon Construct both have long enough durations that you might want to cast them ahead of an anticipated fight. You might also be able to wait to cast Revivify or Greater Restoration until after the fighting is over, depending on the circumstances.

Answer 2

Spells with somatic components and costly material components as well as spells with somatic components and material components that consume during casting require a free hand.

The rules for material Components state:

A spellcaster must have a hand free to access a spell's material components — or to hold a spellcasting focus — but it can be the same hand that he or she uses to perform somatic components.

Due to the class feature Tools Required all of the Artificers spells have a material component. So the hand that holds your infused equipment, which functions as a focus, can perform the somatic component.

The Artificer must have a free hand to handle the material spell components which the infused item cannot replace.

See the SAC guidance on Components:

If a spell’s material components are consumed, can a spellcasting focus still be used in place of the consumed component? No. A spellcasting focus can be used in place of a material component only if that component has no cost noted in the spell’s description and if that component isn’t consumed.

So you need no free hand for your Artificer (S, M) and (V, S, M) spells, unless that M is a costly component or that casting consumes the component, then you need a free hand to handle it.