Nuts

[Andy B]

When my Dad was in the aircraft industry, Vickers and DeHaviland he said there were standards about how many threads should show through a nut but it went in one ear and got lost as I was only interested getting my wheels on the road to go chase girls.
My question; how many threads is safe automotively and specifically nylock nuts if they are different?

[clockwork]

As long as you can see a full thread above the nut it`s ok.:)

[WayneB]

The minimum is 2 threads exposed, ideal is 3 to 4.

Reason behind this is the first two or three threads are not usually formed as well as the following threads and may not be able to hold a load as well.

I like to see 4 myself as on a racing car it it good to see at a glance whether a nut has started to back off and obviously with 4 threads the nut will take longer to loosen off before it parts company with the bolt.

Nylocs should only be used once (as you probably already know) and the 2 thread rule still applies IMO.

As a coincedence my dad once worked at Vickers Aviation (Elmdon UK) and De Haviland (Downsview Canada).