Help please! Anybody know what thread .....

[AES]

....... those (seemingly internationally standard) fittings are for mounting light fittings on things like standard lamps, table lamps, etc, etc, are please?

I'm talking about those very thin nuts plus lengths of tube of various lengths of outside threaded tube which sometimes look like brass but which are all probably steel, sometimes tricked up to look like brass - I mean those fittings where you can screw either a UK bayonet bulb fitting, or Euro screw bulb fitting onto, say, a bottle or vase or turned wooden piece to make a lamp.

Over the years I've collected quite a few of these (both nuts and threaded tubes) and they all seem to fit each other, hence my assumption of an "international standard" above.

I now need to bore and thread a piece of ali bar with a female thread to take one of these outside threaded "light fitting" tubes. Trouble is, despite my collection of all sorts of odds n sods in taps (and dies), nothing seems to fit. Measured dimensions are:

OD (thread crest) = 9.61/9.62mm or 0.375 ins.

ID (thread root) = 9.12mm or 0.362 ins.

From a battered set of thread gauges I have, it LOOKS LIKE a BSW thread form (55 degrees) and using a magnifying glass it LOOKS LIKE it's 25 TPI - maybe 24 TPI.

I thought that back in the "dark ages" (as domestic electricity became the norm - sorry for the pun) the BA series of threads was developed specifically for domestic electrical gear, but obviously the above 0.375 ins OD is way outside the largest BA thread - OBA, or about 0.2 something ins.

Strangely both my Zuess tables and my ME Handbook are silent on this, and not knowing exactly what these "light fitting bits n bobs" are really called, Googling hasn't helped.

Any steers much appreciated - I just need to drill and tap one hole to suit.

TIA

 

[sunnybob]

http://www.lampshademaker.com/lamp_pipe_size_chart.htm

 

[lurker]

British standard pipe ???

 

[AES]

Well, "blow me down!" (and all that). This Forum never fails does it?

Thanks lurker, I never ever considered "BSP" (not that I've got many such taps and dies anyway, but I'll have a check now, see below):

Sunnybob, thanks for that link, it's a goldmine of info for that sort of stuff - not that I'm into lamps & stuff all that much, but "you never know" do you? So it's now book marked, thanks a lot.

At least I now know what to buy/look for now, but does anyone want to have a go at educating me further please?

The lady on Bob's web link talks about my "standard" light fitting stuff being, QUOTE one eighth IP UNQUOTE. I presume that means one eighth inch (wall thickness of the tube - that's what my tube seems to be, and as posted originally, it is three eighth OD), so that sounds just like "my" bits of tube and those slim nuts alright. I also presume that the "IP" means "International pipe"?

But why refer to the WALL thickness instead of the OD? I have little knowledge of BSP threads (they are 55 degrees thread form, that I did pick up somewhere) but if my surmise is correct, why oh why would the "standard" be to refer to the wall thickness of the tube/pipe, instead of the OD of the thread, which is the standard in just about every other thread I've ever heard of? Strange eh?

Anyway, thanks again chaps, and BTW sunnybob, we had our first LIGHT powder snow all day yesterday, our first frost last night, and it's reached the grand high of +2C all day today. So NO more talk of outdoor showering, shorts and flip flops and stuff. It's OVER for the year this side of the Med, OK Bob? (hammer) (hammer) (hammer)

 

[AES]

Well, "blow me down!" (and all that). This Forum never fails does it?

Thanks lurker, I never ever considered "BSP" (not that I've got many such taps and dies anyway, but I'll have a check now, see below):

Sunnybob, thanks for that link, it's a goldmine of info for that sort of stuff - not that I'm into lamps & stuff all that much, but "you never know" do you? So it's now book marked, thanks a lot.

At least I now know what to buy/look for now, but does anyone want to have a go at educating me further please?

The lady on Bob's web link talks about my "standard" light fitting stuff being, QUOTE one eighth IP UNQUOTE. I presume that means one eighth inch (wall thickness of the tube - that's what my tube seems to be, and as posted originally, it is three eighth OD), so that sounds just like "my" bits of tube and those slim nuts alright. I also presume that the "IP" means "International pipe"?

But why refer to the WALL thickness instead of the OD? I have little knowledge of BSP threads (they are 55 degrees thread form, that I did pick up somewhere) but if my surmise is correct, why oh why would the "standard" be to refer to the wall thickness of the tube/pipe, instead of the OD of the thread, which is the standard in just about every other thread I've ever heard of? Strange eh?

Anyway, thanks again chaps, and BTW sunnybob, we had our first LIGHT powder snow all day yesterday, our first frost last night, and it's reached the grand high of +2C all day today. So NO more talk of outdoor showering, shorts and flip flops and stuff. It's OVER for the year this side of the Med, OK Bob? (hammer) (hammer) (hammer)

 

[Inspector]

The 1/8" etc., refers to the nominal inside diameter of the pipe and fittings not the wall thickness. Leftover from the days of steam perhaps?

Taps and dies from a company in the USA if you can't find some at home. Seventh group down the page for the taps and second for the dies. They have a $25 minimum order.

https://www.victornet.com/subdepartment ... /1290.html
https://www.victornet.com/subdepartment ... /2570.html

Pete

 

[lurker]

I have no knowledge of how they got going, but my assumption is it arose from folks modifying light fittings from gas when electricity started to take over.

I make this assumption having recently removed some steel gas light pipe embedded in the plaster of my current terraced "doer upper" which was built in 1880. Frightened the life out of me when I found it! . Had to rip a decent t&g floor up to check they were isolated.

I never checked the threads but they looked like bsp to my inexperienced eye. It was Thick wall pipe too, half inch od but I bet the bore wasn't a quarter inch.

 

[sunnybob]

Way back when, gas pipe was made in 1/4".
I was a gas fitter apprentice from 1964 on and often fitted gas fires and lights with it. Although gas lighting by then was very rare and only found in very old houses.

Then a few years later copper pipe was allowed for gas use (previously copper was only for water). At that point the smaller iron pipe became obsolete due to the effort in cutting and threading it compared to running 1/2" and 1/2" copper.

 

[AES]

Thanks a lot again to you all, sunnybob, Inspector, and lurker. What you all say makes good sense.

All the bits of light fitting tube I have are much thinner-walled than that (i.e. the bore is much bigger than quarter inch) but I guess that makes sense for light fittings 'cos A) it keeps the costs down, and B) a bigger bore gives more space to get the cabling through, not to mention nil requirement to retain a pressure of what, typically 2 or 3 Bar?

I think I vaguely remember as a very young kid moving into an old house (similar age to yours I think lurker), and my dad being similarly worried about finding some old gas pipe buried in the wall somewhere.

And special thanks to Inspector for that link for a source of suitable taps. I do have a pretty competent tool vendor just down the road from me, but if I get no joy there I've got your link bookmarked, thanks a lot. As it happens our house (built mid '60s) does have iron pipe for water so perhaps it will not be a big deal to find BSG here in Switzerland.

Last Q to you knowledgeable folk please - is BSP and BSG the same thread form?

Once again, many thanks folks, I've learnt something new.

 

[sunnybob]

Just checking... you should have Galvanised iron pipe for water. yes?
Ordinary mild steel pipe should never used for water, only gas. #-o

 

[AES]

Yes, quire correct Bob, the water pipes here at home ARE galvanised. Though having said that, the water in our area is so "hard" (full of both calcium and sand stone) that on a couple of bits of pipe I've had to renew so far, both have been so badly clogged that only about half the original bore is available for water flow (and on "environmental grounds" full-system salt de-chalkers are NOT allowed here).

 

[CHJ]

Anyway, thanks again chaps, and BTW sunnybob, we had our first LIGHT powder snow all day yesterday, ….. ..

Any particular reason you had to share it!!!! or were you just being your usual benevalent self.

Forced to endure it today whilst visiting here
Youtube Vid

 

[Inspector]

We had snow on the first day of fall! =D> Do I get a prize? :wink:

 

[sunnybob]

Would everybody please note that I DO NOT LIKE snow. To the point that I HATE snow, even when its on christmas cards adn inset pictures that take me by surprise.. (hammer) (hammer) (hammer) (hammer)

Whats my name? 8) 8)

I hope youre not not drinking that water Andy. You know thats how you get kidney stones dont you?

Our village water here is well water, and bearing in mind Cyprus is a volcanic island, you aint seen furred pipes till youve seen Cyprus furred pipes.

Bottled water is for drinking, and its very cheap here. I think if I were you i would work on the principle of what they dont know wont hurt you, and fit a decent filter system out of sight of prying eyes.

 

[AES]

Ah 'tis filtered (heavily) sunnybob, and all sorts of "cleaning" (externally) as well, but my better half ONLY drinks bottled water, and apart from teeth brushing and the odd "schluck" for things like medication I don't drink much tap water either.

Re the snow - not a problem if you've got your winter tyres installed already (what der yer mean, "no such fing 'ere?"), and if the streets are regularly swept - which we have and they are CHJ. But must say it does get a bit parky these nights sitting at the stop waiting for the tram back home after choir practice (AND we've got an open air concert on 15th December to boot.

Where are you exactly Inspector? And when does Autumn begin (officially) with you?

"Nuffink rong wiv snow" Bob, you just need to be equipped for it

 

[sunnybob]

I got frozen to death several times in the late 70's and early 80's. Even wearing 27 items of clothing (yes, i was so cold one day I counted every sock and glove).
never again will I volountarily walk through, or even see snow.

we are into autumn now, midday still reaches 20c or slightly higher, down to single numbers overnight though.
8) 8) 8)

 

[AES]

You should have tried working outside doing "line maintenance" on RAF fighters in N Germany in January as I did Bob! Mind you that was in the 60's and I'm NOT saying I'd be rushing to volunteer for such work these days!

BTW, back in the day, did you ever try womens' tights under your long johns Bob? And it doesn' arouse any comments 'cos all your mates are wearing the same. Keeps you warm, but again I'm not so sure I'll be doing it now.

 

[Inspector]

Saskatoon, Saskatchewan, Canada. Fall begins the same as yours does on the fall equinox. This year it was the 22nd of September. It warmed up a few days after that but the snows have been back a few times since then and has been on the ground for the last couple weeks. I have studded tires on the 4x4 pickup (as does the wife's little SUV) because I don't like sliding into things when it is icy. :wink: Nights have been down to -20C a few times and will be down to -40C in a month or two. Dress warm and keep the car plugged in.

So that's the weather report and after the commercial we will get back to our story about threading lamp parts. (hammer)

Pete