Looking for the part number for a 1994 XJS 2+2 battery terminal bolt. Mine is getting worn. The bolt that tightens the terminal clip to the actual batteyr post/terminal.

 

Most local/neighborhood hardware stores will have a thread gauge, and if you can fully unscrew the bolt and take it out, you go to the hardware store and find out if it's metric or SAE and the thread pitch (they are usually set up or located in the aisle where nuts and bolts are located). Once you have that info you should be able to find a suitable replacement at the hardware store or you will have the necessary info to order it online.

However, are you sure it's the bolt and not the terminal itself that is wearing out? From your photo, my concern would be that the terminal might be a softer material than the bolt itself.