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