The kind that fits. Nobody is going to be able to tell what kind of diameter and thread pitch that is by just looking at a picture of it.
If I had to guess, probably metric. Clean it out thoroughly, take it to the hardware store, and start test fitting. If you have a thread pitch gauge you can at least figure out the pitch, and if you have a pair of calipers you could measure the inner diameter and take a pretty good stab at the bolt diameter, as well.
This is all predicated on it being a standard thread pitch of some description because the manufacturer was cheap, and not something bespoke because they were bastards.
There may be an off chance that someone has an example of the same/similar (most likely Chinese mass produced) item, and has already done the legwork. It’s worth a shot, but unlikely.
The kind that fits. Nobody is going to be able to tell what kind of diameter and thread pitch that is by just looking at a picture of it.
If I had to guess, probably metric. Clean it out thoroughly, take it to the hardware store, and start test fitting. If you have a thread pitch gauge you can at least figure out the pitch, and if you have a pair of calipers you could measure the inner diameter and take a pretty good stab at the bolt diameter, as well.
This is all predicated on it being a standard thread pitch of some description because the manufacturer was cheap, and not something bespoke because they were bastards.
The old school ones were actual plumbing parts screwed together, and modern iterations use NPT threading to this day. Probably 1/2"
It’s just real cheap metal. I didn’t expect anyone to measure it for me. I thought there might be some common solutions to this
It’s anodized aluminum, for sure.
There may be an off chance that someone has an example of the same/similar (most likely Chinese mass produced) item, and has already done the legwork. It’s worth a shot, but unlikely.
I’ve been smoking pot since the 80’s, and every head shop I’ve ever been to sells the cap OP is looking for. You can even get them on Ebay.