I really don't like not knowing stuff so I'm hoping someone might know the answer. I've measured a Veritas Jet and as close as I can determine, the thread is 4.5mm dia, 0.5 pitch. The closest imperial measurement would be 3/16 inch, 27 (or 28) tpi but this doesn't seem to belong to any standard I can find. The closest match is a Metric Fine thread, which is 4.5mm x 0.5 pitch, but I cannot believe a British manufacturer would have used a Metric standard. Does anyone know what the thread type actually is? BTW, it's the same thread as an Austramax jet if anyone knows what that is.
*UPDATE* I just checked my tap and die sets and discovered I've got a 1/16 BSF 32tpi (both tap and die) so I checked these against a Veritas jet and it's not the same! The die binds after roughly a single turn and putting the tap up against the thread it's noticeably different. As I mentioned before, close as I can measure a Veritas jet has a thread pitch of 27tpi or possibly 28tpi. 27 would be more likely as there are a number of threads that use 27tpi. Anyhow, it's neither a BSF or a UNF thread so I'm stumped again. I plan to re-engineer and modify a larger jet with the correct orifice size but I'll need a die to re-cut the threads. Ho-hum, I'll have to do more digging.
In the opening post of this thread, Colin mentioned the Austramax nipple thread: I’ve just determined the thread on the Austramax nipple to be UNF 10-32. Wotking on a Coleman table lamp, I needed to cut a brass hanger to screw into the shade holder post. By trial and error I found a screw to fit the shade holder post then measured its thread as UNF 10-32. In discussion with @ROBBO55 about this Coleman project, we discussed this topic of Colin’s. Martin got back to me and said he’d measured the thread on the Austramax nipple as UNF 10-32. So… this morning I tested the UNF 10-32 thread I’d cut into a 4.6mm brass rod, and it fits the Austramax generator like a glove: [I’d probably get clearer photos in better light] Here is the same thread screwed into a Coleman burner screw: Thanks, Martin, for you assistance with the Coleman project. @ColinG Later this morning I’ll check this out against a Veritas. Cheers Tony
@ColinG I’ve checked the thread on a Veritas nipple and vapouriser and can confirm that it is UNF 10-32. Cheers Tony
@Tony Press You're welcome Tony, always happy to help. I didn't have a 10-32 UNF die / tap to work with. Must get one now. Colin, I'm wondering if it is a standard Veritas nipple that you are mesauring. Side note, whilst the small diameter UNF and BSF are similar the thread angle differs 60 deg and 55 deg. When practical, I usually find cutting a test threas better than using a tap or die when checking compatability.
OK, it's officially time to put me out to pasture I reckon! I measured again today and swapped jets and measured again and it's 32tpi - no question! I don't know what i was measuring a few days ago but all I'm seeing with my thread pitch tool today is 32tpi. Apologies guys. It must be my age... or something!?! So heres a photo of one of my Superbs with a jet I thought was enlarged. Seems it wasn't! Excuse the frosted globe. It's an American Mantle model for a gas lantern that kinda, sorta more or less fits.
@ColinG Don’t worry about being put out to pasture. I’ve been in the pasture for a while now and it’s pretty good, so welcome to the paddock mate. There’s a lot of us here. Cheers Pete
Colin, no problem. Measuring small threads can be difficult and with so many to choose from makes it more confusing. . I've certainly had issues and got it wrong. I'm glad the thread size had been sorted. Good luck with your project.
I would need a magnifying glass to see if the threads match those on the gauge and against a background of bright light when measuring 32 tpi. It'd take quite a while for me to verify my measurements too.
