Threaded rod into brass tube

[Michael O’CallaghanParticipant @michaelocallaghan36064]

I have an M18 mild steel tube and wanted to put a threaded rod with a threaded Rod Connecting Nut to fit snugly inside, but I don't want to buy the wrong size and have to return it.

Could some one please tell me what size threaded rod I should order.

Thanks

[Michael O’CallaghanParticipant @michaelocallaghan36064]

Didn’t know the right size

[pgk pgkParticipant @pgkpgk17461]

The question cannot be answered without knowing the wall thickness and therefore the internal diameter of that tube.

pgk

[peak4Participant @peak4]

I assume M18 refers to 18mm Outside Diameter, but to work out which nut would fit, you need to know the Inside Diameter, or at least the wall thickness of the tubing to work it out

This Link will take you to a table of Across Flat/Across Corner dimension of metric nuts. There are many similar tables on the net for other threads/spanner sizes.

So say your tube is 18mm OD wall thickness 1.5mm then ID is 15mm.

M8 would be too loose @ 14.3mm M10 too tight @ 17.8mm

Your only option would be to look around for a different thread, or file a bit off each of the corners of the nut.

I'm assuming you don't have access to a lathe to do the job.

Bill

[WearyParticipant @weary]

If I have understood your question correctly the following may assist–>

This table gives the standard metric nut dimensions across the corners, you can check which will best fit your tube and thus which threaded rod will be most suitable. Or, alternatively you could purchase tube to fit a chosen size of studding and connector. Your connector could of course be lightly machined to reduce the across the corner dimension whilst retaining enough flat to apply whatever torque you may require.

I am assuming that your studding connectors retain nut dimensions as this table would indicate – excepting the length which should be three times the thread diameter!

 

Regards,

Phil

 

And Peak4 types far faster than me!! *chuckles*

Edited By Weary on 09/08/2018 10:27:41

[Martin ConnellyParticipant @martinconnelly55370]

Why do you need a coupler in the tube? You can get threaded rod studding in 3m lengths.

Martin C

[HopperParticipant @hopper]

Is this still to make a mad tool to pull wire tight to hold wire mesh to fence posts, to keep cats out of your garden, like in your last thread? I've found that twisting wire with pliers is plenty good enough to keep cats from getting through a mesh fence. Also using cable ties works well.

8mm threaded rod and joiner nut should fit.

Edited By Hopper on 09/08/2018 11:18:22

[Nick HulmeParticipant @nickhulme30114]

Posted by Michael O'Callaghan on 09/08/2018 09:55:42:

I have an M18 mild steel tube

Is that M18 Coarse, Standard or Fine Pitch?

[HopperParticipant @hopper]

Posted by Nick Hulme on 09/08/2018 12:35:49:

Posted by Michael O'Callaghan on 09/08/2018 09:55:42:

I have an M18 mild steel tube

Is that M18 Coarse, Standard or Fine Pitch?

A fine pitch will provide more force per turn than a coarse one, allowing the OP to pull his wire harder.

[Author]

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