Here some distinctions between thread, wire and string.

We have

String [from Mathematics]:

A string of length L on an alphabet A of n characters is an arrangement of k not necessarily distinct symbols from A:

http://mathworld.wolfram.com/String.html

Physics string:

Strings are one-dimensional extended objects. Typically, a string has length in Planck length units, 10^{-35}:

https://en.wikipedia.org/wiki/String_(physics)

In general, a string is a path defined by a particle moving through space.

Wire [from Engineering]:

Conductor. A path for current. Wires closed paths for electrons and such paths are usually much shorter than strings.

Thread [from Physics]

The thread dislocations introduced by a nanoindentation were observed as V-pits, where the photovoltage was lower than that on plane surface under ultra-violet illumination (see the attached image) [from]

Single thread dislocations in gallium nitrides by Kelvin probe force microscopy

Xu, Ke;Applied Physics Letters, 17 December 2012, Vol.101(25)

The wires often refer to a thin metal piece or wire that is twisted into one thicker wire. While the thread and thread, well, the string is usually thicker than the thread, but the definition is considered intended use. The thread is used for sewing, while the thread is used to tie things together.

string is usually much thicker than thread, Thread is used for sewing, whereas string is used for tying objects together. Wire almost always refers to a thin AND SLIGHTLY LONG piece of metal,

There is a difference. The thread is an approximation with an infinitely small radius and it can be electric or magnetic. Wire is only a conductive object. And the string emphasizes its constancy of form. My opinion.