Author Topic: Now heres a thing  (Read 198 times)

Offline a101960

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Now heres a thing
« on: 09.10. 2017 11:30 »
The nut and bolt enigma. How is that now and again a nut will not start on a bolt thread, but if you turn the nut around and try again it will screw all the way up the bolt thread with out problem. Another oddity is when you screw a nut up a thread some where during the process it will hit a tight spot and it will need a spanner to get it past this point and then it frees up, but again turn the nut round and it screws on with no trouble at all. I suppose the obvious answer would be damaged the threads, but why by just turning the nut around does the nut screw on?
John

Offline bsa-bill

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Re: Now heres a thing
« Reply #1 on: 09.10. 2017 11:55 »
I know what you mean - I would put forward this suggestion, it could be a game of two threads, so the thread on the nut has a fault on one side of one thread, the stud is similar, so putting the nut on one way around means the two faults meet, where as the nut on the other way means they don't.
All the best - Bill
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Offline a101960

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Re: Now heres a thing
« Reply #2 on: 09.10. 2017 13:11 »
Quote
I know what you mean - I would put forward this suggestion, it could be a game of two threads, so the thread on the nut has a fault on one side of one thread, the stud is similar, so putting the nut on one way around means the two faults meet, where as the nut on the other way means they don't.
Yes Bill, that sounds reasonable. It might also explain why when this occurs another substitute nut will screw on just fine, and the nut that will not screw on is fine when tried on a different thread.
John

Offline Sluggo

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Re: Now heres a thing
« Reply #3 on: 09.10. 2017 17:50 »
Maybe its just the wingnut turning the spanner???   In the military for tactical aviation all work is documented in the log book or maintenance forms.  A common term is R squared, (R2) which stands for Removed & Replace.

On occasion the pilots will make a mistake and write up a maintenance problem or fault to try to cover up the actual problem.  Nothing is more difficult to replicate is a intermittent or non existent fault in order to ID the repair needed.  Sometimes after extensive testing we have to document that fault not found.
No longer allowed but for a while my supervisor would write them up as.....
"Issue not verifiable, no defects found, R2 Stick actuator".

But all parts are made to a tolerance, In manufacturing you make it to the print and customer specs, call outs, and accepted deviations all need to be documented especially for parts made for medical, Military, transportation or Aerospace.  My wife currently  is Master scheduler as well of Goddess of expediting.  Worked most every position in the company.   Known as the old world term of
"Screw machine shop"  Threaded parts are only part of the equation.   The engineering staff can explain it better, but threads have a classification for fit & finish, and the metal surfaces have specs for finish as well.

If you would like a quote for a run of specialized parts or fasteners they do small runs.  (Small runs are usually several thousand pieces but everything is graded to scale.)  Brass, Steel, aluminum, stainless and whatever surface finishes you want, plating, anodizing, or heat treat...

See: http://www.enochmachining.com/
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