Need help identifying thread of La Spaziale steam tip

#1: Post by **bsafnuk** » May 20th, 2010, 5:59 pm

As the subject suggests, I'm trying to identify the thread on the steam tip of the La Spaziale Vivaldi. In particular, the one sold by chriscoffee:

http://www.chriscoffee.com/products/hom ... lesteamtip

It does not seem to be a standard metric or imperial thread. The outer thread diameter is 0.334" (8.48mm) and the distance between threads is approx. .036" (.9mm) (28 tpi).

Any help would be greatly appreciated.

Thanks,

Brad

http://users.rcn.com/erics/ · #2: Post by **erics** » May 20th, 2010, 8:53 pm

I guess it wouldn't make you feel any better if I said those are the same diametrical dimensions on the Bezzera BZ07 steam tip? Except I measured the pitch to be 0.80 mm (32 tpi). 28 tpi would be a 1/8" BSPP number but yours (and mine) diameter is too low.

May 20th, 2010, 11:21 pm

It is certainly possible that I measured inaccurately and it is actually 32 tpi - I don't have a thread gauge, and there are only 2 threads total so I was not that confident in my stated thread pitch. Of course, if it is a custom diameter and pitch, that doesn't help me too much

Any thoughts on if it would thread into a 9mm hole with 1mm pitch?

http://users.rcn.com/erics/ · #4: Post by **erics** » May 21st, 2010, 12:25 am

Yes, I believe it is a custom thread. It would thread in BUT because you said there are only two threads available - that would lead to stripped threads real soon. Not only that but M9 x 1.0 is too readily available either.

edit - I don't think it would thread in - I just tried an M8 x 1.25 into the female thread for the "custom" M8.5 x 0.80 and it did not catch any threads - slipped right in.

May 21st, 2010, 2:41 pm

It wasn't pretty, but I got it to thread into a hole drilled to .300 and tapped with a 1/8-NPT tap. It doesn't bind at all, but after 2 or 3 threads the taper in the tap makes the hole too big. It seems like it is a different thread than your Bezzera tip - 28tpi seems to be correct, and mine would not fit into any M8 nut.

Anyways, it is good enough to work, which is all that matters in the end.

Thanks for your help.

#6: Post by HB » February 23rd, 2022, 7:45 am

Reopening this long-dormant thread at the request of member WWWired for an update.

WWWired wrote:As the original post mentioned a steam tip, the original poster must have meant "inner diameter" of the threads (female threading on steam tip).

The measurements provided by the original poster when put in this context make perfect sense.

It is likely a 1/8" BSPP thread and the original posters indication of 28 TPI would be fully correct for a 1/8 inch BSPP female thread. As well, the original poster's listed thread diameter of 8.48 mm is so close to the inner diameter for a female BSPP 1/8" thread, of 8.495mm, as to be within about 0.18% (about half the width of a human hair).

It's possibly a 1/8 inch BSPP (or BSP or G type) thread. The current post as it is could be difficult and lead to folks using incorrect NPT or Metric threaded items on a BSPP thread.