I have a table originally compiled by Andy Pugh that covers about 520
standard threads in the following thread systems and did not get a hit.
Good luck!!:

BA = British association. CEI = Cycle Engineers Institute.
ADM = Admiralty. M = ISO Metric. Whit = Whitworth.
UNF/UNC = Unified national Fine/Coarse. BSF = British Standard Fine.
W.INS = Whitworth Instrument. W.Pipe = Whitworth Pipe Thread
Brass = Brass thread. PROG = Progress Thread.
BSP = British Standard Pipe Thread. WALTH = Waltham Thread
PEND = Watch Pendant Thread. GAS = Gas (Brass Pipe) Thread
THURY = Swiss Screw Thread. ASME = ASME Thread.
HOLTZ= Holtzapfels Threads. LOEW = Loewenhertz Threads.
SPARK = Spark Plug Threads. Elgin = Elgin watch screw threads (L = left
hand thread)
CROWN = Watch crown threads. BUTTON = Watch button threads
COND = Steel conduit thread (DIN 40430)




Buerste wrote:
"Nicht die Bohne" wrote in message
...
Hello everyone!

I restore vintage espresso machines and right now I have one machine
with really strange threads, which are used on pipe connections. The
machine was manufactured in Italy in the 50s. Here are some examples:

TPI 20 diameter 14.9mm = 0.5866"
TPI 20 diameter 19.25mm = 0.7578"
TPI 16 diameter 20.25mm = 0.7972"
TPI 16 diameter 22.8mm = 0.8976"
TPI 16 diameter 27.7mm = 1.0905"

Does anyone know what kind of threads it might be?

Many thanks,
Julius

It's "IBT" standard. (Italian ******* Thread)