“Carrying” items without an eruv

Question

I have seen people use "Sabbat belts" and bracelets that use the key as some functional part of the item (eg something that holds the loop together).

However, this does not seem to be a real garment of any sort (talking here about items that would generally be covered up, not displayed, like a bracelet under sleeves)?

What is a general principle regarding these types of items?

Note: I seem to recall reading that there are really two types of garments, ornaments and "real" garments, where garments are real pieces of clothing (some minimum size?) and ornaments are meant to be worn to enhance one's appearance. I don't have a source for this though.

Answer 1

Chicago Community Kollel reports that

if the key serves a purpose it is considered “clothing” eg where “pin of a belt buckle” is replaced “with a key”. But “If one is wearing a belt already, the “key belt” is no longer serving a function and should not be worn.

Another method used to transport a key on Shabbos is to use the key as part of a tie clip. However, this is only permissible if it is serving the function of holding the tie in place. If one’s sweater or vest is already holding the tie in place, the key tie clip is not serving any function and cannot be worn.

However, if the key tie clip is made of gold or silver it may be considered a tachshit (adornment) and is subject to the rules mentioned above concerning a pin⁄brooch”

(that is, in short, that you would wear it for decoration on a weekday too.)

In a question to Revach, the questioner quotes from a teshuvah from Reb Moshe Feinstein to the effect that one cannot use a tie-belt to keep ones shirt or tie in place (because one would not do it on a weekday).

In summary, if a key is part of a belt that serves a useful function, it has the halakhic definition of “clothing”. If it is genuinely decorative, it is an adornment and can be worn on Shabbos.

But I need help to understand the story about Rabbi Moshe Feinstein, where it is reported that Reb Moshe showed his "tie clip" key to a student. “It was a simple, non-ornamented key with a tie clip attached to its back.”