What is it??....Machinists?

This "tap" was in a box with other parts I bought at a swap meet a number of years ago. No one I've shown it to has any idea of it's use. Anyone here?

Here is a description:
Overall length: 6 1/2"
Thread cutting teeth section length: 4 1/4"
6 rows of "flutes" (?)
12 threads per Inch
Small end: 7/8" Dia.

It actually is in better shape than the picture would suggest. There is some etched information on it about "SPL TH".

Thanks in advance if you can solve the case of the "mystery tap"
Large end of teeth: 1 3/8" Dia.

 

I thought it was a reamer but it does look like it has threads. Maybe a giant pipe tap, or some other kind of tapered thread?

 

hmmm. i was thinking pipe tap too. the SPL TH did some one put that on there or do you think it might have came that way? I checked my hand book and found nothing like that.

 

i was going to say a pipe tap too. Aren't there any markings on it?

 

It looks like a tap for a somdrige fitting on a drippelmot valve.I have'nt seen one of those in years.

 

the "spl th" would lead one to think "special thread"
It maybe to enlarge a hole then add threads in one p***?
tt

 

The SPL TH marking looks just like it was printed in ink, not hand etched or hand stamped with the little # & letter type stamps. I've been around various types of pipe threads and have never seen any with that much taper. The taper it most closely resembles is like that on drill rods for well drilling but on a miniature scale.

 

No, you're probably thinking of the single taper somdrige fitting. This actually has the subtle taper of the "barrel somdrige". HA!

 

It is a pipe tap for tapping out ball valves?

 

As in; for replacing seats in a br*** ball valve? Hmm..... Maybe it went home in a plumbers lunchbox by accident?

 

I'd bet that its a pipe tap meant for multiple size holes... Grab a couple different pipe plugs and their size pipes, tap in and see if you get the 3-4 threads before it binds up.

If it'll give you 3-4 threads, its a cool tool... I'm betting it wont quite do that, looks like a "great idea" thats mostly impossible to impliment!

 

I would guess that it's an **** probe left behind by aliens.

 

Rocknrod.....You just might have it! I'd think it might work on 1/2" or 3/4" and up to about 1 or 1 1/4" NPT. I'll check it on some fittings tomorrow. I woundn't think the T.P.I. changes much, if at all, through those sizes.

 

HRTH, Interesting theory. YOu wouldn't happen to have any experience with that kind of equipment would you?


Frank

 

I'm usally the prober, not the probee.