Google's John Mueller said on Twitter, - whatever - you can use either the inch sign when saying something is 10" or you can can write it out and say something is 10 inches. It doesn't matter, Google doesn't prefer either option.
Here are the tweets on this question:
Just use these things naturally - no need to do anything artificial.
— 🍌 John 🍌 (@JohnMu) July 29, 2019
There is no special weight for either of those.
— 🍌 John 🍌 (@JohnMu) July 29, 2019
Yea, so Google doesn't care if it is inches or " - got it?
Forum discussion at Twitter.