Any idea how to screw a nylon-insert locknut backwards onto a threaded
rod (i.e., nylon section of nut should thread on first)? I want to
back the nut onto the end of a long rod, thread the rod a little ways
into a plate, then tighten the nut against the plate. Thanks.

--
Drew

wrote in message
...
Any idea how to screw a nylon-insert locknut backwards onto a threaded
rod (i.e., nylon section of nut should thread on first)? I want to
back the nut onto the end of a long rod, thread the rod a little ways
into a plate, then tighten the nut against the plate. Thanks.

--
Drew


Run it on the proper way first, to form the thread in the nylon portion of
the nyloc, then reverse it and give it a go. It would likely be to your
advantage to slightly taper the end of the threaded rod to assist the nylon
in getting started due to spring back of the nylon, which is what makes it
work as a locking nut. Keep in mind, too much turning will reduce the
tension, so move it a bare minimum.

Harold

Harold and Susan Vordos wrote:


wrote in message
...
Any idea how to screw a nylon-insert locknut backwards onto a threaded
rod (i.e., nylon section of nut should thread on first)? I want to
back the nut onto the end of a long rod, thread the rod a little ways
into a plate, then tighten the nut against the plate. Thanks.

--
Drew


Run it on the proper way first, to form the thread in the nylon portion of
the nyloc, then reverse it and give it a go. It would likely be to your
advantage to slightly taper the end of the threaded rod to assist the
nylon
in getting started due to spring back of the nylon, which is what makes
it
work as a locking nut. Keep in mind, too much turning will reduce the
tension, so move it a bare minimum.

Also watch out for burrs on the thread--nylon is soft and a small burr or
nick can cut a real thread in it, which destroys its tension.



Harold

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

don't use a nylon type lock nut for this , they are intended as a single use
, have you considered a thread locking solution , or using a castellated nut
and swaging it after tightening

There are several all-steel locknuts avalable from aircraft
parts places, or even from the average aircraft repair shop. They're
used in hot areas like the engine compartment, or in areas where the
manufacturer has reason to specify them. One popular type looks a bit
like a castellated nut but the slots are very narrow and the top end is
crushed just enough to give good friction. The threads run all the way
through. Their friction is higher than the nylock, and the thread fit
is class 2, much better than the average cheapnut. There must be ten or
fifteen neat locknut types for just about any oddball application.
Check yer Yellow Pages under Aircraft Parts or Aircraft Repair.
See http://www.aircraftspruce.com/menus/ha/nuts.html and scroll
down to All Metal Stop Nuts.

Dan

Harold and Susan Vordos wrote:


Run it on the proper way first, to form the thread in the nylon portion of
the nyloc, then reverse it and give it a go. It would likely be to your
advantage to slightly taper the end of the threaded rod to assist the nylon
in getting started due to spring back of the nylon, which is what makes it
work as a locking nut. Keep in mind, too much turning will reduce the
tension, so move it a bare minimum.

Harold


Thanks for the taper idea; that does the trick. (I had been thinking
along the lines of solvents or heat to soften the nylon.) These things
are really tight: they are 1/2" nuts so there's plenty of nylon in
there, I guess.

--
Drew

williamhenry wrote:

don't use a nylon type lock nut for this , they are intended as a single use
, have you considered a thread locking solution , or using a castellated nut
and swaging it after tightening


Thanks, I did look at them at mcmaster but they are too expensive for
my purpose. I got a box of the SS/nylon nuts that are supposed to be
"re-useable" (for a couple of times, anyway). They are less than a
buck apiece. The nylon seal will be a plus as well.

--
Drew

wrote in message
...
Harold and Susan Vordos wrote:


Run it on the proper way first, to form the thread in the nylon portion
of
the nyloc, then reverse it and give it a go. It would likely be to your
advantage to slightly taper the end of the threaded rod to assist the
nylon
in getting started due to spring back of the nylon, which is what makes
it
work as a locking nut. Keep in mind, too much turning will reduce the
tension, so move it a bare minimum.

Harold


Thanks for the taper idea; that does the trick. (I had been thinking
along the lines of solvents or heat to soften the nylon.) These things
are really tight: they are 1/2" nuts so there's plenty of nylon in
there, I guess.

--
Drew


Happy to assist.

Harold

wrote:

There are several all-steel locknuts avalable from aircraft
parts places, or even from the average aircraft repair shop. They're
used in hot areas like the engine compartment, or in areas where the
manufacturer has reason to specify them. One popular type looks a bit
like a castellated nut but the slots are very narrow and the top end is
crushed just enough to give good friction. The threads run all the way
through. Their friction is higher than the nylock, and the thread fit
is class 2, much better than the average cheapnut. There must be ten or
fifteen neat locknut types for just about any oddball application.
Check yer Yellow Pages under Aircraft Parts or Aircraft Repair.
See http://www.aircraftspruce.com/menus/ha/nuts.html and scroll
down to All Metal Stop Nuts.

Just for the record, I spent a good deal of the taxpayer's money resolving a
problem involving elastic stop nuts on a military aircraft a while back.
The following is based on that experience--it's not my uninformed opinion.

Nylon insert elastic stop nuts are typically rated for 50 reuse cycles. If
the threads are clean and not burred, they'll do a few more than that
before the torque drops below the value required by the specifications--how
many more depends on the finish quality of the bolt, whether it has a dry
film lubricant coating, how clean it is, and other factors which we were
never able to identify.

If the threads are burred or have abrasive material on them then the torque
can go below spec in a single cycle.

There is a temptation to use all metal elastic stop nuts on the basis that
they are more "durable". They aren't--I was specifically told by my
supervisor to consider an all metal nut and I found out that they are not
rated to last nearly as many cycles as Nylon, and they don't--their primary
utility is for high temperature areas where nylon would melt.

If you want _real_ durability there are nuts with a Vespel (chemically
related to Kevlar) insert that are rated for 500 cycles, and we had a guy
in the lab to run a bolt in and out of a bunch of those things 500 times
with a torque wrench, to confirm that they really worked as
advertised--they do. But a burr on the fastener can still take out the
insert quickly.



Dan

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)