[TOMT] Looking for a heavy steel ball with a clasp

I’ve only seen people ask for songs, shows and movies in this community, so I’m not sure if this is the correct one. Anyway, as explained in the title, I’m searching for a ball of steel (weighing 0.5kg or more) with a clasp to hang on my chain. Can I find anything of that sort? If so, any clues on where and what to look for? I tried searching using the description I provided, but to no avail.

For reference, the chain has an anchor design and and a width of 9.5mm