What's the standard hex nut for locks?

[Tobes]

Hi all,

I have a couple of locks which came with a cab which don't have the nut used to secure the lock to the door. I think they are M18 nuts but I'm having a hard time figuring out the exact ones. I don't really need to buy a couple of new locks if possible.

Any advice appreciated!

 

[69er]

Hi all,

I have a couple of locks which came with a cab which don't have the nut used to secure the lock to the door. I think they are M18 nuts but I'm having a hard time figuring out the exact ones. I don't really need to buy a couple of new locks if possible.

Any advice appreciated!

The threads differ by manufacturer … usually a fine thread pitch and while nut inside diameter is around 18mm the outer diameter or metric spanner size is often M22 but some are M24 the tongue nuts also vary while most tighten with a M11 spanner again the threads are usually fine and vary between makes..
In all honesty used locks and even new ones are cheap enough to not find you end up with a wrong nut , stiff or even cross threading?
If you know the lock make by key I have hundreds of nuts here and a picture of the key might enable a guess at the actual nut size?
Either way the nuts are not normally available separately in shops?

 

[Tobes]

They are a couple of First locks. Front panel tubular one with F750 markings, believe it to be this one.
Then the coin box lock which I believe is a F830 but I can't see any markings on the lock to confirm it other than the keys have Kind Lock. So it looks like its a M19 Nut, I think the thread might be 1mm.

I might just have to order some nuts and give it a try.

 

[69er]

Metric nut sizes are measured by the spanner size as here M22 tho the thread shaft body of the lock varies .
There is no M19 inside diameter nut… an M19 spanner nut fits an M12 metric bolt shaft
Most locks are made to fit a 19mm hole and as seen here have M22 nut.
The chart photo shows the thread diameters go up in 2mm increments. and thread pitches vary on other makes tho some I would agree will be 1mm pitch. So you need a nut fitting 1mm pitch on a 19mm body ….any complete machine locks fitting a 19mm hole will fit . As 19mm bolt thread diameter is not a size and nuts are made to fit lock body they come with..

Over the years I have had loads that ‘fit’ but when picked out randomly can be stiff or a bit wobbly on the threads when not manufactured together… it’s sad that they are nice locks but still inexpensive to buy new on eBay or even here on ukvac . Put a wanted post in “Wanted” someone may have spare ones that same make?

The only specific measurement you need then is the approx body length in your case just over 1 inch (27mm) by that tech diagram but the length can be ‘tweaked’ by a slight bending of the tongue ideally in a vice not when on the 7mm spindle as it might snap it?