Mystery pipe tap

[30-30remchester]

Just acquired this 1/2" pipe tap apparently for people who don't like getting close to work. It also have small through holes near the tip. Does anyone have any insight?

 

[30-30remchester]

For some reason I can't post an additional photo that shows the overall length of 10".

 

[Beerhippie]

It doesn't look tapered to me--other than the starter threads.

There isn't a bore through the length of it, is there? Thinking the holes could be for lube.

 

[30-30remchester]

There are 2 holes bored completely through. Kind of looks like for a wire. It says it is for 1/2" pipe.

 

[Oregon Dave]

Agree with Beerhippie, from the pic, not much taper for a pipe tap; cutters typically taper in width, narrower at the tip.

Otherwise just a John Bath Co. extension tap to reach places std. lengths can't.

Not even a hint of a clue on the hole; have a LOT of taps, never seen it before - can not image a functional use for it - suspect it would require a certain skill set for a user to want and then drill it.

 

[The Cobbler]

with no taper would indicate is it a NPS(straight) rather than NPT(taper) tap. no idea on what the holes would be for .

 

[Old Man Roger]

For some reason I can't post an additional photo that shows the overall length of 10".

Explains why I didn’t get the joke.

 

[Provincial]

Those extra-long taps are called "Pulley" taps. Flat-belt pulleys often extended over the hub and had a clearance hole to get at the set screw. The long shank taps were needed to tap that hole working from the outside diameter.

 

[nadogail]

i have been told on good authority that conduit threads threads are the same form and pitch as pipe threads but are straight instead of tapered.

 

[RTM]

Those extra-long taps are called "Pulley" taps. Flat-belt pulleys often extended over the hub and had a clearance hole to get at the set screw. The long shank taps were needed to tap that hole working from the outside diameter.

Thanks, did not think in that type of pulley. I bought one for retapping a breast drill chuck for a friend, only one in the size I needed

 

[PCustoms]

Is there a hole up through the shank?

 

[30-30remchester]

No other holes except shown, there are actually 2 sets of holes opposite each other, and both extend all the way through to the opposite side.

 

[Beerhippie]

Ah, those holes are so the bellhanger can pull the bell wires after tapping the hole.

 

[alfadan]

If there was a hole in the end, I'd think it to be a through-coolant tap.

 

[Beerhippie]

If there was a hole in the end, I'd think it to be a through-coolant tap.

But no bore down the shaft--already covered that.

 

[humber2]

It could be a nut tap for threading successive lok nuts or union couplings.

YMMV