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MG Midget and Sprite Technical - Triumph style TRE nut thread and size please

Anyone know the thread and size of the nyloc nut on the Triumph style TRE please?

My TREs are from First Line, part number FTR4072, if that makes any difference.

I tried metric and UNF nuts but neither seemed to want to start catching the thread properly so I didn't try too much and refitted the original nyloc nuts but I'm not keen on doing that.
Nigel Atkins

Don't hold a gun to my head on this Nigel, but it's in the back of my mind they're BSF. That said repro TREs may well be different.

If you don't like reusing nylocs (which is sensible) you might consider investing in a little bottle of Loctite. It goes a long way.
Greybeard

Hi Grey,
the Moss site has it as GHF223 which when using Paul's translator page comes out as 3/8" UNF which I first thought of and tried but it didn't seem to start threading well.

The rack arm and TRE locknut seemed to fit metric spanners better than imperial so I sent my wife off to buy some 10mm nuts. It was a very hot part of the day and I don't do well in heat so I decided to chat with neighbours the very long time my wife was away (turned out she got distracted shopping for a new settee).

I now can't remember if I tried the existing nut on a 3/8" UNF bolt I have or not!

I've got some blue threadlock left so the next time the front wheels are off I'll check or replace the nuts and use the threadlock if required.
Nigel Atkins

Looking at my car the locknuts have a blue nylon insert which almost certainly means its a metric thread - as a comparison UNF/UNC will have a clear(ish) insert.

However I have a feeling they may be M10 fine thread not the standard coarse thread which has a pitch of 1.5mm whereas M10 fine has a pitch of 1.25mm
Martyn Wilks

Thanks Martyn that starts to make sense, they are blue inserts and I did try both the usual metric and UNF and neither seemed right.

I know a place that might probably sell M10 fine.
Nigel Atkins

Yes similar on the track rod ends on our Suzuki Jimny.

The nut was in bad shape and I went into my extensive metric collection and nothing fitted.

I have loads of M12 x 1.5mm nuts and bolts. That one was metrick fine M12 x 1.25mm.

I now have a good selection of metric fine nuts and bolts which I assume I will never use but they are there just in case as it is always a Thursday night you find you need one and it's great to have one to hand.
Eddie Cairns

I wouldn't assume anything about the nylon locking insert collar colours unless I had some sort of standard to indicate it was so as a product I do uses M8 nylocs and they typically come from a local supplier in blue and white (translucent) , they vary depending on supplier I guess. My understanding is that in the UK only Metric coarse was standardised and all else was optional so what you think is Metric fine is someone elses standard, for me I do a few items that use M10 x 1mm and that is similar to 3/8" UNF.
David Billington

Thanks, Eddie and David, there's a shop that sells nuts loose so I can try a few of each when I next get a chance to get out there, or I'll have to trust my mate to get them and bag and label them correctly.
Nigel Atkins

Yes the 3/8 UNF and 10mm x 1mm are virtually the same size.

On a TRE only use carbon steel, in metric sizes use grade 8.8 or higher. Never stainless but you know that.

M10 x 1mm nuts if you cannot find locally.

http://www.ebay.co.uk/itm/10mm-12mm-14mm-16mm-18mm-20mm-24mm-x-1-1-25-1-5mm-Fine-thread-pitch-Nyloc-nuts-/232272980723?var=&hash=item36148c6af3:m:mDgl2pN1oNnIELSwPrVuBqA
Eddie Cairns

Thanks Eddie,
I've bookmarked the link in case I or my mate can't get to it over the next while, I'm 20 miles away but he's only 5.
Nigel Atkins

Just to end this thread properly -

Triumph style TRE nut size and thread is -

M10 x 1mm (thread) (17mm spanner)

- as per Eddie's correct advice, and fitted this afternoon.

Out of interest I also got some M10 x 1.25mm and M10 x 1.5mm as well to see if I could see the difference in threads with my eyes when they're side by side, and I could.
Nigel Atkins

This thread was discussed between 29/05/2017 and 28/10/2017

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