Chosen Solution

Aside from length (3.1 and 2.3), what is the size,- width and thread pitch - of the lower case screws for the MBP mid-2015 retina 15? I have a lightly stripped hole that I’d like to chase w a tap if I can find one that size.

Daniel Stra those are M1.2 by 2.3mm and 3.1mm length respectively. Your local jeweler might just have the right Tap to chase the thread. As for the pitch the coarse is 0.25mm and the fine is 0.20mm. Get both or just use one of your screws to measure it.

As a former jeweler, I doubt you will find one with those screws; but as a former Mac Store owner and repair person, I think you would have much better luck with a Mac repairman having those screws.