Battery terminal stud thread?

[Amulet]

I have two XM dual purpose batteries on Amulet (CXV90's). They have "dual post terminals". I am doing some rewiring, and I need to use the studs as well as the conventional terminals. Problem: I can't find a nut which fits them. They look like M8 but are a different, coarser, thread. No nuts were supplied with the batteries - though I think they are now (at least at my chandler - who won't give me any!). Can anyone tell me what thread these things are? I have emailed XM but am awaiting their reply.

Graham.

 

[VicS]

The "normal" M8 thread has a pitch of 1.25mm. There is a finer one (1.00mm) but not coarser.

5/16" is very close to 8mm (less than 0.1mm smaller) so possiblly 5/16 Whitworth That has a pitch of 0.0556" (18tpi) which is a gnats over 1.4mm.

5/16 UNC is also 18tpi so that is another possibility.

The shape of Whitworth and UNC threads are slightly different, the main difference being that Whit threads are 55° while UNC are 60°

My guess then if very close to 8mm, 5/16" Whit or UNC (In reality you will be pushed to see the difference between the two)

 

[nedmin]

Hah for the good old days of Whitworth,BSF and BA at least if Whitworth rusted up you had a good chance of undoing it.not like some of these modern types

 

[halcyon]

5/16" whit is the standard for battery studs.

Brian

 

[flyingscampi]

I bought a XM battery recently and there should be a bag crudely sellotaped to the outside of the battery containing the nuts. I know this because I couldn't find a nut that fitted and went back to the Chandler who gave me the bag from another battery...

Good luck with XM!

 

[Amulet]

Thx Brian - that's a precise and economical answer.

flyingscampi - your chandler is more accommodating than mine. I tried to persuade them to nick the prominently sellotaped nuts off another battery. No luck.

 

[halcyon]

If you need one let me know, I drop it in the post.

Brian

 

[Amulet]

Re: Battery terminal stud thread? 5/16 UNC

From the horse's mouth: XM say it's actually 5/16 UNC, and they are putting some in the post for me.

From what I hear, I could probably screw a 5/16 Whit on without much grunt.

Graham.

 

[aquaplane]

Seven years later and I have exactly the same question, this thread came up about the 5th result on a Google search.

I tried an M8 nut on and it sort of fits but is a bit sloppy.

Monday lunchtime trip to Danlett Fasteners coming on I think

Thanks for the info.

 

[aquaplane]

The -ve terminal is 5/16" BSW and the +ve is 3/8" BSW I have found.

At least that's what fits on my batteries.

 

[Bilgediver]

I have two XM dual purpose batteries on Amulet (CXV90's). They have "dual post terminals". I am doing some rewiring, and I need to use the studs as well as the conventional terminals. Problem: I can't find a nut which fits them. They look like M8 but are a different, coarser, thread. No nuts were supplied with the batteries - though I think they are now (at least at my chandler - who won't give me any!). Can anyone tell me what thread these things are? I have emailed XM but am awaiting their reply.

Graham.

For some curious reason they are 5/16 UNC. I got my Wing nuts in Vancouver Canada....