[Nate Nagel]

Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. I thought to myself,
"self, if I had a tap for that thread I could make the rod any length
she wanted, and not be limited to the foot-long increments that come
with the fixture." Well, she was happy with no downrod at all in the
location it was going (hung from bulkhead over kitchen sink) but it got
me thinking, what the heck *is* that thread? Google suggests it is a
"straight pipe thread" but what size? Does anyone make sets of those
taps for a reasonable price? Even McMaster-Carr only sells them
individually (for over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

[WW[_2_]]

"Nate Nagel" wrote in message
...
Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. I thought to myself, "self,
if I had a tap for that thread I could make the rod any length she wanted,
and not be limited to the foot-long increments that come with the
fixture." Well, she was happy with no downrod at all in the location it
was going (hung from bulkhead over kitchen sink) but it got me thinking,
what the heck *is* that thread? Google suggests it is a "straight pipe
thread" but what size? Does anyone make sets of those taps for a
reasonable price? Even McMaster-Carr only sells them individually (for
over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Nate... I do a lot of desk lamp building and repair. The size is 1/8 X 27
thread per inch. Ace hardware will have both taps and dies. 1/8 x 27 NPT.
(national pipe thread. WW

[dpb]

On 5/3/2011 7:19 PM, Nate Nagel wrote:
....
...those nipples that are used all over the place in lighting. ...
... what the heck *is* that thread?...

They're 1/8" NPT...

--

[Nate Nagel]

On 05/03/2011 09:01 PM, dpb wrote:
On 5/3/2011 7:19 PM, Nate Nagel wrote:
...
...those nipples that are used all over the place in lighting. ...
... what the heck *is* that thread?...

They're 1/8" NPT...

--

NPT is tapered innit?

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

[WW[_2_]]

"Nate Nagel" wrote in message
...
On 05/03/2011 09:01 PM, dpb wrote:
On 5/3/2011 7:19 PM, Nate Nagel wrote:
...
...those nipples that are used all over the place in lighting. ...
... what the heck *is* that thread?...

They're 1/8" NPT...

--

NPT is tapered innit?

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

YES ww

[Smitty Two]

In article ,
"WW" wrote:

"Nate Nagel" wrote in message
...
Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. I thought to myself, "self,
if I had a tap for that thread I could make the rod any length she wanted,
and not be limited to the foot-long increments that come with the
fixture." Well, she was happy with no downrod at all in the location it
was going (hung from bulkhead over kitchen sink) but it got me thinking,
what the heck *is* that thread? Google suggests it is a "straight pipe
thread" but what size? Does anyone make sets of those taps for a
reasonable price? Even McMaster-Carr only sells them individually (for
over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Nate... I do a lot of desk lamp building and repair. The size is 1/8 X 27
thread per inch. Ace hardware will have both taps and dies. 1/8 x 27 NPT.
(national pipe thread. WW

NPT = National Pipe Taper
NPS = National Pipe Straight

I can neither confirm nor deny that the thread in question is 1/8-27,
but I'm sure you'll agree it's not tapered.

[DD_BobK]

On May 3, 8:44*pm, Smitty Two wrote:
In article ,









*"WW" wrote:
"Nate Nagel" wrote in message
...
Was helping cousin hang a pendant type light fixture over the weekend..
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. *I thought to myself, "self,
if I had a tap for that thread I could make the rod any length she wanted,
and not be limited to the foot-long increments that come with the
fixture." *Well, she was happy with no downrod at all in the location it
was going (hung from bulkhead over kitchen sink) but it got me thinking,
what the heck *is* that thread? *Google suggests it is a "straight pipe
thread" but what size? *Does anyone make sets of those taps for a
reasonable price? *Even McMaster-Carr only sells them individually (for
over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Nate... I do a lot of desk lamp building and repair. The size is 1/8 X 27
thread per inch. Ace hardware will have both taps and dies. 1/8 x 27 NPT.
(national pipe thread. WW

NPT = National Pipe Taper
NPS = National Pipe Straight

I can neither confirm nor deny that the thread in question is 1/8-27,
but I'm sure you'll agree it's not tapered.

Bingo! NPS = National Pipe Straight


My local Ace did not have the 1/8"-27 NPS (straight pipe thread) die
nor tap.
I balked at the McMaster prices & bought them from MSC online.

Great lamp parts source http://www.grandbrass.com/

Lamp part sizes IPS 1/8, 1/4 & 3/8
IPS meaning iron pipe size (but some say it's internal pipe size)

Lamp parts are typically NPS (National Pipe - Straight)
as opposed to the much more common plumbing thread NPT (National Pipe
- Tapered)

THREAD SIZE Actual Unthreaded OD
1/8 -27 NPS .405"
1/4 -18 NPS .540"
3/8 -18 NPS .675"

To add to the confusion NPS is an abbreviation that is also used to
denote "nominal pipe size"

When I first started to repair some ancient lamps & wall sconces,
I had a very hard time figuring out what the parts were made from.



cheers
Bob

[Evan[_3_]]

On May 3, 8:19*pm, Nate Nagel wrote:
Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. *I thought to myself,
"self, if I had a tap for that thread I could make the rod any length
she wanted, and not be limited to the foot-long increments that come
with the fixture." *Well, she was happy with no downrod at all in the
location it was going (hung from bulkhead over kitchen sink) but it got
me thinking, what the heck *is* that thread? *Google suggests it is a
"straight pipe thread" but what size? *Does anyone make sets of those
taps for a reasonable price? *Even McMaster-Carr only sells them
individually (for over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel


Being able to thread the outside surface of a rod or hollow tube
using only a tap would be a neat trick man...

What you are looking for is called a die...

Sets of piping dies cost megabucks because normally only
a tradesmen or machine shop would even want to look for
such a thing...

~~ Evan

[Smitty Two]

In article
,
Evan wrote:

On May 3, 8:19*pm, Nate Nagel wrote:
Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. *I thought to myself,
"self, if I had a tap for that thread I could make the rod any length
she wanted, and not be limited to the foot-long increments that come
with the fixture." *Well, she was happy with no downrod at all in the
location it was going (hung from bulkhead over kitchen sink) but it got
me thinking, what the heck *is* that thread? *Google suggests it is a
"straight pipe thread" but what size? *Does anyone make sets of those
taps for a reasonable price? *Even McMaster-Carr only sells them
individually (for over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel


Being able to thread the outside surface of a rod or hollow tube
using only a tap would be a neat trick man...

What you are looking for is called a die...

Sets of piping dies cost megabucks because normally only
a tradesmen or machine shop would even want to look for
such a thing...

~~ Evan

Machine shops likely have a collection of dies around, but they're not
much used because unlike taps, they don't lend themselves to automation.
Outside threads are cut on a lathe, either with a box tool, or with a
"single point" cutter that is the shape of one thread and tracks the
length of the thread to be cut.

[N8N]

On May 5, 5:52*am, Evan wrote:
On May 3, 8:19*pm, Nate Nagel wrote:





Was helping cousin hang a pendant type light fixture over the weekend.
Fixture came with solid downrod that screwed together with those nipples
that are used all over the place in lighting. *I thought to myself,
"self, if I had a tap for that thread I could make the rod any length
she wanted, and not be limited to the foot-long increments that come
with the fixture." *Well, she was happy with no downrod at all in the
location it was going (hung from bulkhead over kitchen sink) but it got
me thinking, what the heck *is* that thread? *Google suggests it is a
"straight pipe thread" but what size? *Does anyone make sets of those
taps for a reasonable price? *Even McMaster-Carr only sells them
individually (for over $20 apiece!)

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

Being able to thread the outside surface of a rod or hollow tube
using only a tap would be a neat trick man...

What you are looking for is called a die...

Sets of piping dies cost megabucks because normally only
a tradesmen or machine shop would even want to look for
such a thing...

No, I'm looking for a tap, the downrod was made of tubing with a
little standard lighting nipple at each end. So if I wanted a custom
length, I would have cut the tubing, squared off/dressed the end, then
tapped it so the nipple could be threaded back in.

nate