Threaded tube for lamp

[Iwilldoit]

Hi
I am trying to repair a cfl floor standing reading lamp which has snapped off at the base part of the cast thread has broken away. there was only about an inch of thread being used but can see a fix which is to use a longer threaded rod and add some epoxy around the broken part.
My problem is I cannot find the correct size rod. It measures 11.8mm outside diameter including the thread and inside is about 9mm. In inches the outside is just a bit smaller than 5/8.
The other issue is that the thread is 1.25mm pitch according to my pitch gauge but everything seems to be 1.0mm. Also i need it to be about 10cm or 12cm long.
I have searched the net with no luck.
Thank you.

 

[333rocky333]

The common size for lghting is 10mm x 1mm pitch, google that and add hollow lighting rod, not many sellers sell longer than 1 metre lengths

 

[Iwilldoit]

The common size for lghting is 10mm x 1mm pitch, google that and add hollow lighting rod, not many sellers sell longer than 1 metre lengths

Thanks - for clarity I need 10 or 12cm not 1000mm
Yep its not 10mm or 1mm pitch I am repairing for a relitive but I have found the lamp on Amazon and it seems to be an weak spot

https://www.amazon.co.uk/Kenley-Natural-Daylight-Floor-Lamp/dp/B00N31PFYO/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1

 

[SUNRAY]

As you and Rocky says the usual size for this is 10mm and 1mm pitch.

5/8" = 16mm. If it is 16mm I wonder if it could be 16mm conduit.


Could you provide any pictures to give us a better idea of the problem?

 

[Iwilldoit]

As you and Rocky says the usual size for this is 10mm and 1mm pitch.

5/8" = 16mm. If it is 16mm I wonder if it could be 16mm conduit.


Could you provide any pictures to give us a better idea of the problem?

Thank you yes it is this. These are from other people on amazon. The threaded part on the tube is just not long enough to catch enough thread. I need the 1.25 pitch as hat is the part you can see has part broken off.
That 1/4 segmented bit you can see I plan on filling with epoxy to extend the broken off threaded section and strengthen the area.

 

[Iwilldoit]

Here is the part I need in a longer version of. Dont worry about the flat side or the non threaded section - all thread is ok. You see the dark area at the top of the tube, that is all that was in the shaft of the floor standing lamp that has a weight in the base so it easily snaps. so I hope to fix it with a longer threaded tube and epoxy

 

[SUNRAY]

Is 12mm x 1mm pitch any use?

https://www.ebay.co.uk/itm/184681056060?

https://www.ebay.co.uk/itm/321252115560?

Drill out any threaded part in the light fitting?

 

[jj4091]

Could you saw off the broken section then epoxy a nut into place that will accept the old threaded tube instead.

 

[SUNRAY]

Looking at this with fresh eyes I'm struggling to see how this all fits together, is it something like this with the threaded tube tightened against the base with a couple of nuts/washers then the silver broken part screwed onto it and tube slides on and held in place with a screw or two

If that is the case could you drill right through at 12mm to clear the 12mm threaded tube such as I linked to (there may be better deals to be had) and use a 3rd nut/washer

 

[Iwilldoit]

Is 12mm x 1mm pitch any use?

https://www.ebay.co.uk/itm/184681056060?

https://www.ebay.co.uk/itm/321252115560?

Drill out any threaded part in the light fitting?

Great idea thanks

 

[Iwilldoit]

Could you saw off the broken section then epoxy a nut into place that will accept the old threaded tube instead.

Another great idea

 

[Iwilldoit]

Looking at this with fresh eyes I'm struggling to see how this all fits together, is it something like this with the threaded tube tightened against the base with a couple of nuts/washers then the silver broken part screwed onto it and tube slides on and held in place with a screw or two

View attachment 418733
If that is the case could you drill right through at 12mm to clear the 12mm threaded tube such as I linked to (there may be better deals to be had) and use a 3rd nut/washer
View attachment 418734

Thanks for all your work on this

 

[Iwilldoit]

Ok I have some pictures
You can see how weak and thin the cast is.
This first photo I could break off the right hand wall of the remaining thread and epoxy in place a nut. to line it up I can just put the nut on the old threaded tube and screw in the tube into the 1/2 inch thread that remains then fill the whole segments you see with epoxy. The segments are only about 1.5 inch deep and have a closed end at the bottom

 

[Iwilldoit]

Thank you yes it is this. These are from other people on amazon. The threaded part on the tube is just not long enough to catch enough thread. I need the 1.25 pitch as hat is the part you can see has part broken off.
That 1/4 segmented bit you can see I plan on filling with epoxy to extend the broken off threaded section and strengthen the area.
View attachment 418699View attachment 418700

If you look at these photos from amazon reviews the threaded short lamp tube is fixed in place with a nut top and bottom through the weighted base then when you assemble it all you just screw the fist section on pole on to it. The wiring is connected with snap connectors before you attach the next pole section

 

[Iwilldoit]

My problem now then if I was to just glue in a nut is I cannot find the correct size. I cant seem to find a cosponsoring "M" size nut for the tube which is 11.8mm outside diameter and a 1.25 pitch.

According to google an M12 nut has a 12mm diameter so is my 11.8 diameter threaded tube for an M12 nut.
I will google.