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MG TD TF 1500 - What nut?

I'm trying to determine what knurled nut size I should get for my turn signal (after market). The threads are 1 mm but I can't find a chart telling me what M size is (M10, M12, etc) based on the 18 mm diameter of the threaded barrel. Any help would be appreciated. If anyone has a nut of the correct size I would be happy to buy it.

Tim

And of course i forgot to attach the picture....again! See next post.
Timothy Burchfield

After market turn signal.

Timothy Burchfield

Tim-
I'm a little confused by your photo and description. What does the 18 mm represent; a "flat-to-flat" dimension? Or?

If you're certain it's a 1 mm thread then in the super fine category you only have two options I believe.
10 mm X 1 mm or 12 mm X 1.25 mm.

Can you clarify?

Roy
Roy Challberg

Roy, it is not flat to flat it is the distance between the threaded sides. I looked up 18 mm nuts but none come in 1 mm (checked with thread gauge). As you probably know the metric system is akin to black magic in the States. I can't see how a 10mm nut would fit on an 18 mm dia threaded cylinder? I'm sure I'm missing something.

Thanks

Tim
Timothy Burchfield

Tim,
If the thread diameter is 18mm then you have two options, an 18mm course thread has a pitch of 2.5mm and the fine thread has a pitch of 1.5mm. I would check if it is the fine one first.
John
J Walton

Thanks John. The thread, checked with a thread gauge is 1 mm. I haven't been able to find a nut for the 18 mm threaded cylinder on the switch with that thread pitch. I dropped the old nut in the car when I was adjusting the switch and even with taking out the carpet I haven't bee able to find it.

Tim
Timothy Burchfield

Google:
M18 1 nut

Quite a few to choose from.

Lonnie
TF7211
LM Cook

Tim
It has always amazed me that the US never really swapped over to metric
It's not really a dark art
If the thread is 18mm outside diameter then it is refered to as an M18 meaning metric 18mm
If the pitch that you have measured is 1mm
then you need a-
M18X1mm nut
People refer to metric as fine or course thread but really there are endless variables
For example you could have a 10mm bolt with
1mm pitch or 1.25 or 1.5 or 1.75 or 2mm
The choices are endless
Cheers
willy
William Revit

L.M. Cook is right -
18 mm X 1 mm can be bought (extra,extra, fine thread), but they certainly don't give them away!

Good luck,
Roy
Roy Challberg

Lonnie, I found some but I was looking for the knurled nut that came on the switch. Thanks

Willy, I think most Americans know in their hearts that the metric is a better system. It is jut pretty difficult for most people to wrap there minds around the concept. Everyone knows how big an inch is but not 2.5 cm. I should have realized that an 18mm nut was an M18. I'm just happy that I recently learned the 28 C is about 82 F.

Roy, Declan Burns gave me a couple of sites where they are available. Thanks.

Thanks everyone for your help. I turn 70 this month so I need all the help I can get (that's 112 in metric years).

Regards

Tim
Timothy Burchfield

Tim -

It’s a long shot, but look in the electrical / misc section of an auto parts store. Dorman and other suppliers sell blister packs of switch bezels etc.

Lonnie
TF7211
LM Cook

Cheers Tim
It's around 2'C (35F)overnight here at the moment and topping out at about 12'C (54F) during the day
We're just getting into Winter but really the weather is quite mild
Happy 112th birthday Tim

lol
willy
William Revit

Lonnie, thanks.

Thanks Wille. It's been 90F (32 C) here the last week. It's like a we are in different hemispheres. :-)

Cheers

Tim
Timothy Burchfield

Tim,
M18x1mm nuts are used widely in industry. They are commonly used to mount standard 18 x 1mm proximity switches.
The applicable standard is DIN 439.
Here's a source in Europe if it is any help
https://www.ebay.de/itm/Muttern-Din-439-Feingewinde-flach-M-18x1-NEU-2-Stuck/310386286961?hash=item484476e171:m:mRCd_kS-0NSP10KV-h34PmQ
https://www.ebay.de/itm/Sechskantmutter-M18x1-06-A4C-Feingewinde-gelb-chromatiert/222391588393?hash=item33c7925629

Regards
Declan
Declan Burns

Any time I need a nut for a smallish piece, I take it to my local hardware store (that sells metric nuts and bolts) and I try different nuts until I find one that fits.

Tom
T Norby

Tom, I'd hardly call an M18 a smallish nut. I visited the local small hardware store, the big box stores and the online fastener companies. Even with the good advice above I never did find an M18 knurled nut similar to the one that was on the turn signal switch. I did however find the original yesterday after taking out almost all of the interior. It was under the carpet that is on the rear brace under the package shelf. How it got there I will never know.

Regards

Tim
Timothy Burchfield

This thread was discussed between 05/07/2018 and 07/07/2018

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