"unifying thread" is a correct and usable phrase in written English.
You can use it to refer to a common theme or idea that ties together a group of people or a set of ideas. For example, "The unifying thread amongst the students was their shared passion for learning."
What do you see as the unifying thread?
The passage from innocence to experience is the principal unifying thread of these essays, written mostly over the past decade.
"He is the right man in the right position at the right time". The unifying thread to Alexander's work is his desire to punch through bureaucracy and deliver useful intelligence to the battlefield, according to those who know him.
As different as the administration's responses have been to Iraq and North Korea, one unifying thread has been the effort to mobilize international pressure for both countries' nuclear disarmament.
While 2007's fiction promises to sweep from the Welsh valleys to the Peruvian jungle, musing on love, death and other literary staples, it's impossible to ignore a unifying thread: war.
Is this rather thin unifying thread strong enough so that Proposition 105 meets the constitutional requirement that ballot measures deal only with a single subject?
A second unifying thread in all the art here is the fact that the computer and its many graphic functions plays a significant role in their process of creating art.
As noted above, decreased tissue maintenance and rates of regeneration provide a unifying thread between many age-related phenotypes.
As Figure 2 illustrates, this ID must be assigned to patients at recruitment and is thereon the unifying thread through the system's data stores and flows.
Running in between were the clipped, metallic pop songs that gave Revolver its unifying thread.
For Judy Staubo, football and family were the perfect Sunday mix, and the Giants were the beloved unifying thread.
