I have a player whose been playing as an Armorer artificer that is probably going to be captured during the next session, so I've been thinking about what the NPCs can do with his stuff.  The character was originally built before Tasha's came out using the UA rules.  I've started reading the Tasha's description and I'm starting to question what the designed limits of an artificer's abilities are.  The class is described as a magical tinkerer who uses mundane items to cast spells.  An example in the book describes a mechanical spider built to cure wounds.  Additionally, many of the item buff descriptions use "grant the wearer" or similar language to describe the target of effects.  So my question is, are the magical properties/spells of the artificer unique to the artificer or unique to the item?  I think RAI is to make it unique to the artificer, but in my admittedly brief reading of the description, I don't see that in RAW.

I'm not quite sure what you are asking.

If the magical ability imbued into an item by the artificer has wording about "the wearer" then it could be worn by somebody else (unless there is some other rule that comes into play that restricts the thing being worn by only the artificer).

Your thread title also doesn't reflect the question you are asking.

Further clarification as to the discussion interactions you are concerned about would be helpful.

In general the Artificer's spellcasting works the same as any other caster with one exception: all of their spells are considered to have the Material component and they must use a spellcasting focus as part of casting the spell. An Artificer can use thieves' tools or artisan tools they are proficient in, or an item they have infused as a spellcasting focus. An Armorer can also use their Arcane Armor as a spellcasting focus.

As for an Artificer's infused items Farling is correct. When an infusion says "the wearer" then anyone wearing the item benefits from its effects.

Finally the Armorer features Arcane Armor and Armor Model tell us that the Armorer gains their benefits when wearing the armor. To anyone else it is a mundane suite of armor.

I don’t see a way to change the title of the thread.  My bigger question was could the artificer grant any pc access to his spell list through giving the pc the item used in the spell.  Based on the clarification that the items are treated as material components in the spell, I see now that the answer is no.  Also from what was stated above, any mystical abilities imbued in the armor are unique to the artificer and cannot be granted to any other wearer of the armor or any component there of.

ArnItheBest said it well.

Quote from Nuclear_Monkey >>

An example in the book describes a mechanical spider built to cure wounds.  Additionally, many of the item buff descriptions use "grant the wearer" or similar language to describe the target of effects.  So my question is, are the magical properties/spells of the artificer unique to the artificer or unique to the item?  I think RAI is to make it unique to the artificer, but in my admittedly brief reading of the description, I don't see that in RAW.

 You're mixing up some different things here. The line about the magical spider is entirely about flavor rather than mechanics - you cast Cure Wounds in the same way anyone else does, you just describe it as some kind of tinkery effect instead of blue sparkles or magical rainbows or however else other classes might describe their powers. Nothing in that "Magic of Artifice" section has any impact on the rules, as explained in the last paragraph:

Such details don’t limit you in any way or provide you with any benefit beyond the spell’s effects. You don’t have to justify how you’re using tools to cast a spell. But describing your spellcasting creatively is a fun way to distinguish yourself from other spellcasters.

The other thing I believe you're talking about is infusions. Those are temporary magical items created by the artificer, and yes you can give them to other players. But you are limited to a specific list of options and you are limited in the amount of items you can infuse at once - when you first get the feature, you can only do 2. If you try to do a third, the oldest existing one loses its magic.

OP, my only advice is not to conflate UA Artificer with the official Artificer. If you're using UA, it's probably best not to look at all at the official version - so much is different between the two that there won't be any benefit, only confusion. 

If your question is whether or not UA Artificer can give their spell infused items to other people, then the answer is yes they can. It's not exactly broken though, as from what I remember the UA artificer doesn't have much else going for it. 

The "mechanical spider" is just a reflavoring of casting the spell via tinker's tools (by activating a gadget), whether or not you use a Homunculus Servant infusion.