[SML] Thread projection

[Stuart Wheaton]

On 9/18/2014 3:23 PM, Loren Schreiber via Stagecraft wrote:
>
> I believe common practice in theatre is 1.5 to 3 threads, but I'm not 
> sure how much weight that carries with lawyers and such.  What say you 
> all?
>
> Loren
>

With a nylock, you have to pass through it for it to work, with a 
lockwasher, you have to crush it so it grabs and that does not require 
going all the way through the nut.  As far as passing less than all the 
way through, perhaps we need destructive testing to tell us what the 
loss of strength is.  But if the nut cannot work loose it doesn't matter 
how far it passes beyond the nut.  It's probably a lot like the 5 second 
rule for nicopress swages, you want to be sure the nut is on all the 
way, or the tool is fully closed, beyond that it doesn't seem to matter 
exactly how far or how long. The comments about lighting poles seems to 
apply to bolts and nuts in the 1-2 inch diameter range that are bedded 
in concrete and cannot be easily replaced with a proper length, that is 
rarely a theatre situation.

Stuart