Identify a thread

May 12, 2020 Last reply: 6 years ago 19 Replies

I have a thread I could do with some help to identify. It's on a 2 gallon steel container .. so assuming imperial is a good start . It is the male thread on a welded on pipe...



It's a parallel male thread OD : 0.728" TPI : 24



Would have assumed a pipe thread but pitch is too fine. Although undersize, possible it could have been a nominal 3/4"


Beats me. I can find 20 or 28 tpi but not 24 at that diameter.

ISTR finding an odd fine pitch on some sort of steel electrical conduit once.

Are you sure it's a thread and not just narled rings to give grip for a rubber hose pushed on?

Just had a quick look at various threads, and all I can say is that the

24 tpi feels too fine for a major diameter of 0.728"

Are you sure you have the correct dimensions?

knurled.

Or possibly gnarled, if it were a tree.

If not, if there is enough space, cut it off and re cut a tread in whats left to something you can get. Brian

Good call, that is listed here. Not a common size though.

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Except OD is 0.728" which is 18.5mm so cannot be M18. Hence the need to recheck measurements.

Could it be the tread a compression cone and nut goes onto? They are often weird thread rates.

Mike

M19 X 1 seems to have a place in German plumbing. See the following, I haven't done much research!

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M19 x 1 would have a major diameter closer to 19mm/0.75".

I would expect a female M19x1 to have a minor diameter of 17.92mm

That's not a lot of purchase for a male screw with a major diameter of

18.5mm .

Well if it is a 1mm pitch thread the OP already made a 4% error measuring this, so maybe the major diameter is a little wrong?

Thamks. I couldn't think of any spelling that looked right, but knurled is right.

maybe a conduit thread would make sense it is Galv steel

I have checked again with digital vernier and a thread gauge - measurements I gave are correct

that's a possibility.

This is looking like I will need to solder something else on to get to a useful thread.

Or simply use a compression fitting nut and cone to connect a copper pipe.

Mike

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