Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,










--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

On 2/4/14, 8:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

There are strict standards... You see that 'aircraft quality' BS
statement thrown around all the time by marketers.

Only have a few seconds right now, but Google 'AN hardware' for a start.
Note that the vast majority of aircraft threaded fasteners are fine thread.

There are many special fasteners used in aircraft as well.

Erik

On 2/4/2014 10:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Fasteners will be spec'ed by the manufacturer for the purpose as far as
tensile strength, etc., using a specific set of spec's whether they be
military or internal for civilian aircraft. The "Quality" refers to the
QC pedigree that they meet the standard pedigree and have the paperwork
associated for whatever performance spec is pertinent; it doesn't mean
anything specific regarding what that performance spec to which it
adheres is; that's referred to but not the same thing.

It's like the "N-Stamp" for nuclear-qualified pieces-parts for reactors;
the actual spec's met are different depending on what the reqm't is, the
N-Stamp only assures that it was produced according to the protocol of
documentation and certification and record-keeping required which is far
beyond that of "ordinary" material which may, actually, be of precisely
the same actual functional spec.

--

"Bob Lowe" wrote in message oups.com...
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,


"national aerospace standard" or for short, "nas"

https://www.google.com/#q=nas%2Bmil%2Bspec%2Bfasteners

On 2/4/2014 11:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,



If you ever need the absolute best! I've used these in a few
circumstances that nothing else would work.

http://unbrako.com/

Tom Gardner Mars@tacks wrote:
On 2/4/2014 11:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,



If you ever need the absolute best! I've used these in a few
circumstances that nothing else would work.

http://unbrako.com/

Are these things made in India?

On 2/4/2014 10:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards
and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

For the most part, AN series bolts correspond to grade 5

BUT

every nut and bolt has been x-rayed for internal flaws.

http://www.sportair.com/articles/1Aircraft%20Hardware%20-%20What%20You%20Need%20To%20Know.html



http://www.faa.gov/aircraft/safety/programs/sups/standard_parts/media/standard_parts.pdf
Congress enacted theFastener Quality Act
(FQA) (15 U.S.C. 5401). Enacted in 1990,
the FQA has been subsequently amended
several times. However, the basic intent
remains the same, i.e., to ensure the qual
ity of fasteners and to prevent mismarked,
misrepresented, and counterfeit fasteners
from entering the commercial market.


And

CONSIDERATIONS.
When purchasing and installing standard parts, consider the
following:
•
A Certificate of Conformity (C of C) should be provided by the producer
of a
standard part.
•
A standard part should carry a mark indicating the part has been
produced in
accordance with the specification requirements.
•
A part is no longer considered“standard” if it is used in a critical
application that
imposes qualification or quality control requirements beyond the standard
specification.
•
To facilitate traceability, commingling like fasteners from different
lots is not
recommended.
•
Section 21.303(b)(4) provides that acceptable government specifications are
limited to those published by the U.S. Government. Parts produced to a
foreign
standard may, however, be acceptable for in stallation on foreign
type-certificated
aircraft and products.
•
Installation of a standard part must bein accordance with the
requirements of part
43. Generally, a standard part may be replaced with an identical
standard part;
however, substituting standard parts would require a demonstration of
acceptability in accordance with part 43.

On Tue, 04 Feb 2014 16:18:04 +0000, Bob Lowe
wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Yes there are standards. I seem to remember a reference to "AN"
fastenings - the AN said to mean Army-Navy.

Do a bit more research. Perhaps check the McMasters or Aircraft Spruce
site.
--
Cheers,

John B.

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each manufacture
of
Aircraft Quality Hardware have their own standards and are not made to any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Thanks - Oh yes, there can pages and pages of specs, but now I am finding
out why I was never able to see or obtain any of these specs. I would
have to buy a book or two to see these specs. I doubt if anyone is going
to just print too much information on this for free reading on the web.
Of course I'll keep looking but I don't have much hope for this. They
will sell me an MS 39 bolt but it is up to me to know what this is. I
guess there is no Grade Number per se` for an aircraft bolt - just 101
specs. Thanks again.

--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

Bob Lowe wrote:
replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each
manufacture
of
Aircraft Quality Hardware have their own standards and are not made to
any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Thanks - Oh yes, there can pages and pages of specs, but now I am finding
out why I was never able to see or obtain any of these specs. I would
have to buy a book or two to see these specs. I doubt if anyone is going
to just print too much information on this for free reading on the web.
Of course I'll keep looking but I don't have much hope for this. They
will sell me an MS 39 bolt but it is up to me to know what this is. I
guess there is no Grade Number per se` for an aircraft bolt - just 101
specs. Thanks again.


If they are labeling the bolts "aircraft quality" they are probably
not. Every bolt used in aircraft should have a spec. on it. There are
titanium bolts, SS bolts, huck bolts and every other type of fastener
and they all have a spec. on them. I believe that a lot of information
is listed in FAR 43:13 as to bolt specs.

John

On 2/4/14, 7:50 PM, John wrote:
Bob Lowe wrote:
replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each
manufacture
of
Aircraft Quality Hardware have their own standards and are not made to
any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they
are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Thanks - Oh yes, there can pages and pages of specs, but now I am finding
out why I was never able to see or obtain any of these specs. I would
have to buy a book or two to see these specs. I doubt if anyone is going
to just print too much information on this for free reading on the web.
Of course I'll keep looking but I don't have much hope for this. They
will sell me an MS 39 bolt but it is up to me to know what this is. I
guess there is no Grade Number per se` for an aircraft bolt - just 101
specs. Thanks again.


If they are labeling the bolts "aircraft quality" they are probably
not. Every bolt used in aircraft should have a spec. on it. There are
titanium bolts, SS bolts, huck bolts and every other type of fastener
and they all have a spec. on them. I believe that a lot of information
is listed in FAR 43:13 as to bolt specs.

John

Yes, check it out... go here and download a (free!) copy of AC 43.13-1B,
it's about 3/4 of the way down the page.

http://www.faa.gov/regulations_polic...entTopicID/114

The full PDF is about 16.75 MB, but you'll have the option to download
it by individual chapter if you wish.

AC is FAA speak for 'Advisory Circular', they have thousands of them...
43 means it pertains to part 43 of the Federal Aviation Regulations
(FAR's) concerning Maintenance, Preventative Maintenance, Rebuilding and
Alterations. The rest is just the rest.

This is an interesting document, lots of very good information!

The section covering bolts proper begins at 7-34.

The FAA offers loads of other advisory circulars, handbooks and other
training materials, all free just for the download. I suggest one and
all take a look.

Erik

On Tue, 04 Feb 2014 21:14:31 -0800, Erik wrote:

On 2/4/14, 7:50 PM, John wrote:
Bob Lowe wrote:
replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each
manufacture
of
Aircraft Quality Hardware have their own standards and are not made to
any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they
are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Thanks - Oh yes, there can pages and pages of specs, but now I am finding
out why I was never able to see or obtain any of these specs. I would
have to buy a book or two to see these specs. I doubt if anyone is going
to just print too much information on this for free reading on the web.
Of course I'll keep looking but I don't have much hope for this. They
will sell me an MS 39 bolt but it is up to me to know what this is. I
guess there is no Grade Number per se` for an aircraft bolt - just 101
specs. Thanks again.


If they are labeling the bolts "aircraft quality" they are probably
not. Every bolt used in aircraft should have a spec. on it. There are
titanium bolts, SS bolts, huck bolts and every other type of fastener
and they all have a spec. on them. I believe that a lot of information
is listed in FAR 43:13 as to bolt specs.

John

Yes, check it out... go here and download a (free!) copy of AC 43.13-1B,
it's about 3/4 of the way down the page.

http://www.faa.gov/regulations_polic...entTopicID/114

The full PDF is about 16.75 MB, but you'll have the option to download
it by individual chapter if you wish.

AC is FAA speak for 'Advisory Circular', they have thousands of them...
43 means it pertains to part 43 of the Federal Aviation Regulations
(FAR's) concerning Maintenance, Preventative Maintenance, Rebuilding and
Alterations. The rest is just the rest.

This is an interesting document, lots of very good information!

The section covering bolts proper begins at 7-34.

The FAA offers loads of other advisory circulars, handbooks and other
training materials, all free just for the download. I suggest one and
all take a look.

Erik

Anyone remember the issue some years back....where inferior Chicom
bolts had managed to get into the supply chain...counterfit
marked..and caused the loss of some entire engines on airliners as
well as rotor failures etc etc?

http://www.freerepublic.com/focus/f-news/569932/posts

http://www.asminternational.org/pdf/Aug8-12.pdf

http://www.airliners.net/aviation-fo...ain?id=1563279


Gunner

--
"Virtually all members of [radical] groups sincerely believe that
they are fighting the Establishment. In reality they are an indespensible ally
of the Establishment in fastening Socialism on all of us.
The naive radicals think that under Socialism the "people" will run everything.
Actually, it will be a clique of Insiders in total control, consolidating and
controlling all wealth. That is why these schoolboy Lenins and teenage Trotskys
are allowed to roam free and are practically never arrested or prosecuted.
They are protected. If the Establishment wanted the revolutionaries stopped,
how long do you think they would be tolerated?

Leon Trotsky

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each manufacture
of
Aircraft Quality Hardware have their own standards and are not made to any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Hi guys - I am making progress, thanks...found a wealth of info on the
AC43.B-1B concerning identification of the hardware and some torque and
dimension specs but didn't find much on the actual specs other than that,
but I sure haven't read it all. I did come across what may be called a
basic AN Bolt Designator that may be interesting and necessary as a first
step, at: Challengers 101.com/ANBolts. I did find a good site for some
actual manufacturing specs on AN Bolts but then lost it and couldn't find
it again. And I did find a whole lot a places that would like one to buy
this information. I am finding it hard to get into any of the Gov
specific information. I will persevere, and thanks again for everything.

Bob Lowe


--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

On 2/4/2014 6:50 PM, Cydrome Leader wrote:
Tom Gardner Mars@tacks wrote:
On 2/4/2014 11:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,



If you ever need the absolute best! I've used these in a few
circumstances that nothing else would work.

http://unbrako.com/

Are these things made in India?



Looks like it but they are expanding in Europe. (They still make the
best. Not cheap, but the best!)

On 2/5/2014 11:18 AM, Bob Lowe wrote:


Hi guys - I am making progress, thanks...found a wealth of info on the
AC43.B-1B concerning identification of the hardware and some torque and
...

Bob, the real question here is - what are you trying to do?

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each manufacture
of
Aircraft Quality Hardware have their own standards and are not made to any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Hi - Richard, You asked what am I trying to do. Well this can be a multi
fold answer. First of all, I am trying to learn. I use to own an
airplane and I would just buy a bolt without really know what I was
buying. I didn't take the time to determine what may be better - I just
took other peoples word for it as this is not too uncommon, right. For
the last few years I have been drawing hundreds of pictures of a different
Gyrocotors and I thought maybe, just maybe, I could find time to build a
simple one. I use to look at the four fire-wall engine mounting bolts of
my plane and think, if I were doing this I sure would have used heavier
looking bolts. And as you may surmise, I should surely understand the
strength of a bolt to get anywhere with this. Even if I should buy a
'kit' I know that I would be tempted to use a better bolt. And I thought
that I had better learn all I can on just what a better bolt may be. And
then I am always making things out of surplus Mil-spec bolts as stock,
mostly of stainless on my lathe, and again, it would be better to learn
more about what I may be using. I am retired now and I find myself trying
to learn the things that I didn't have the time to do before. That about
covers 'what I am trying to do' Richard...thanks for your curiosity.

Bob Lowe

--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

"Bob Lowe" wrote
in message
roups.com...
...And as you may surmise, I should surely understand the
strength of a bolt to get anywhere with this.

You can make a quick guesstimate of tensile strength from 100,000 PSI
times the area of the thread root or the tap drill. Shear strength is
about half of that, for the shank or thread root, whichever applies.
For better numbers:
http://www.ti64.com/v/vspfiles/asset...ners%20101.pdf
Ksi = KiloPSI.

jsw

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:


Yes Jim - I just looked at your link, Ti64...and book marked it as
'Essential'. And your guesstimation rule is easy to remember. Another
thing, the first time I saw the engine mounting bolts on a 707 right after
it went into passenger service again I was surprised....As I remember they
were three, either 3/4 or 1 inch bolts holding each engine on. Thank you
Jim.


--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

Far as home building aircraft goes.... might I suggest reviewing these?

http://www.faa.gov/aircraft/gen_av/u...amateur_built/

Erik

On 2/6/2014 10:18 AM, Bob Lowe wrote:

I use to look at the four fire-wall engine mounting bolts of
my plane and think, if I were doing this I sure would have used heavier
looking bolts. And as you may surmise, I should surely understand the
strength of a bolt to get anywhere with this. Even if I should buy a
'kit' I know that I would be tempted to use a better bolt.

Bob Lowe

Hi Bob,

Look, I have to say something that could be taken negatively, but I have
to say it. So, in the interest of safety and education consider this...


Bad idea.


Until you can calculate the loads imposed on a fastener, _don't_ make it
stronger. In fact, don't make any changes at all.

Two reasons off the top of my head...

One: consider the structure that the bolt penetrates. A Larger bolt
means a larger hole too. Sometimes that will be ok - but sometimes the
edge margin could be critical and enlarging the boat could weaker the
attach point. In trying to make the structure stronger you could
easily make it weaker!

Two: sometimes structures are designed to fail in a particular manner.
Making a connection stronger in the wrong place could defeat that
strategy and cause a much worse failure to occur.

And three: A proven design doesn't need to be stronger. If anything
it needs to be lighter!

Just looking at a detail (like a 747 engine mount?) one often wonders
how the engine can possibly stay on the wing. But it does, quite well.

It's all in the numbers.

On Thu, 06 Feb 2014 23:41:06 -0600, Richard
wrote:

On 2/6/2014 10:18 AM, Bob Lowe wrote:

I use to look at the four fire-wall engine mounting bolts of
my plane and think, if I were doing this I sure would have used heavier
looking bolts. And as you may surmise, I should surely understand the
strength of a bolt to get anywhere with this. Even if I should buy a
'kit' I know that I would be tempted to use a better bolt.

Bob Lowe

Hi Bob,

Look, I have to say something that could be taken negatively, but I have
to say it. So, in the interest of safety and education consider this...


Bad idea.


Until you can calculate the loads imposed on a fastener, _don't_ make it
stronger. In fact, don't make any changes at all.

Two reasons off the top of my head...

One: consider the structure that the bolt penetrates. A Larger bolt
means a larger hole too. Sometimes that will be ok - but sometimes the
edge margin could be critical and enlarging the boat could weaker the
attach point. In trying to make the structure stronger you could
easily make it weaker!

Two: sometimes structures are designed to fail in a particular manner.
Making a connection stronger in the wrong place could defeat that
strategy and cause a much worse failure to occur.

And three: A proven design doesn't need to be stronger. If anything
it needs to be lighter!

Just looking at a detail (like a 747 engine mount?) one often wonders
how the engine can possibly stay on the wing. But it does, quite well.

It's all in the numbers.





And using a grade 8 ot L99 bolt in place of the specified AN bolt MAY
also cause a failure. Better bolt? By spec, perhaps. In use? Perhaps
not. A grade 8 bolt MAY fail from vibration fatigue where the
"inferior spec" AN would not harden and crack.

On Thu, 06 Feb 2014 23:41:06 -0600, Richard
wrote:

On 2/6/2014 10:18 AM, Bob Lowe wrote:

I use to look at the four fire-wall engine mounting bolts of
my plane and think, if I were doing this I sure would have used heavier
looking bolts. And as you may surmise, I should surely understand the
strength of a bolt to get anywhere with this. Even if I should buy a
'kit' I know that I would be tempted to use a better bolt.

Bob Lowe

Hi Bob,

Look, I have to say something that could be taken negatively, but I have
to say it. So, in the interest of safety and education consider this...


Bad idea.


Until you can calculate the loads imposed on a fastener, _don't_ make it
stronger. In fact, don't make any changes at all.

Two reasons off the top of my head...

One: consider the structure that the bolt penetrates. A Larger bolt
means a larger hole too. Sometimes that will be ok - but sometimes the
edge margin could be critical and enlarging the boat could weaker the
attach point. In trying to make the structure stronger you could
easily make it weaker!

Two: sometimes structures are designed to fail in a particular manner.
Making a connection stronger in the wrong place could defeat that
strategy and cause a much worse failure to occur.

And three: A proven design doesn't need to be stronger. If anything
it needs to be lighter!

Just looking at a detail (like a 747 engine mount?) one often wonders
how the engine can possibly stay on the wing. But it does, quite well.

It's all in the numbers.


Re engine mount bolts. I once had the job of removing the forward
engine mount bolt on an engine on an Air force Boeing 707. The A.F.
was trying some sort of iffy maneuver and the thing stopped flying
about 50 ft above the runway. After the Crash Truck had inspected
things and they taxied in the first inspection showed no ill effects
and everyone was quite impressed. The next morning one of the
maintenance troops commented that the cowling didn't seem to fit quite
right and after uncowling the engine and dragging up stands and much
peeping and peering it was discovered that the engine mount bolts were
bent and the engine was slightly out of line.

Apparently the Boeing engine mount designers DO know what they are
doing :-)

The final decision, by the Depot, was to remove the engine and then
gauge the engine mount brackets in the pylon, measure bolt holes for
elongation and do die checks of everything, which was where I came in
as the front bolt was bent too badly to simply drive out so the
Machine Shop was called for a solution.

After we got the bolt out without any damage to the supporting
structure they fiddled around for some time measuring, checking,
looking and reporting everything back to Boeing and finally about a
month later they hung a new engine and test flew it.
--
Cheers,

John B.

On 2/7/2014 6:34 AM, wrote:

And using a grade 8 ot L99 bolt in place of the specified AN bolt MAY
also cause a failure. Better bolt? By spec, perhaps. In use? Perhaps
not. A grade 8 bolt MAY fail from vibration fatigue where the
"inferior spec" AN would not harden and crack.

Excellent point!

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each manufacture
of
Aircraft Quality Hardware have their own standards and are not made to any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Hi - FWTW, I just cut this from a 737 accident report...Engine mounts on
Boeing jetliners are a major safety issue.
I have always maintained that I would make a poor aircraft designer
because my planes would be too heavy to fly. At one time I was a liaison
at the Grumman plant at Calverton, Long Island and it was after Grumman
had been asked by the Navy to design an F-111 version for them. They
built three with each lighter and after the third the Navy said it was
still too heavy and Grumman said okay, we are not going to build it any
lighter so forget it. So there are aircraft design engineers out there
that may think like me, but only somewhat, I agree. I worked for Douglas
Aircraft and their philosophy was, build it light, and then beef it up
where required later. Thanks,

Bob Lowe



--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

On 2/7/2014 2:18 PM, Bob Lowe wrote:


Hi - FWTW, I just cut this from a 737 accident report...Engine mounts on
Boeing jetliners are a major safety issue.
I have always maintained that I would make a poor aircraft designer
because my planes would be too heavy to fly. At one time I was a liaison
at the Grumman plant at Calverton, Long Island and it was after Grumman
had been asked by the Navy to design an F-111 version for them. They
built three with each lighter and after the third the Navy said it was
still too heavy and Grumman said okay, we are not going to build it any
lighter so forget it. So there are aircraft design engineers out there
that may think like me, but only somewhat, I agree. I worked for Douglas
Aircraft and their philosophy was, build it light, and then beef it up
where required later. Thanks,

Bob Lowe



That was Ed Heinemann's philosophy.

There were a few problems with the original A-4 Skyhawk as a result.
Mostly systems stuff . . .

These first four aircraft were really challenging. They weighed
some 9800# empty and everything seemed to go wrong on test flights.
During these early flights test pilots discovered that the speed
brakes cracked in a high speed dive, the metal flange alongside the
vertical tail peeled back in high speed runs and the slats tended to
hang up resulting in violent accelerated stalls. In addition, the
oil pressure gage was a simple flip/flop gage, with barber poles the
only indication of pump/oil failure.

On the other hand, once the teething problems were ironed out it was
one hell of an attack airplane.

It was reported that the wing had an infinite fatigue life - even if
flown at full combat weight and max Gs.

On Fri, 07 Feb 2014 20:18:02 +0000, Bob Lowe
wrote:

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such
as
bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards'
for this 'Quality'? The best that I can determine is that each manufacture
of
Aircraft Quality Hardware have their own standards and are not made to any
'Industry' standards. I have found out that some manufactures will not
even
give a PSI rating for their nuts and bolts, only stating that they are of
'Aircraft Quality'. Can anyone put more light on this?
Thanks,


Hi - FWTW, I just cut this from a 737 accident report...Engine mounts on
Boeing jetliners are a major safety issue.
I have always maintained that I would make a poor aircraft designer
because my planes would be too heavy to fly. At one time I was a liaison
at the Grumman plant at Calverton, Long Island and it was after Grumman
had been asked by the Navy to design an F-111 version for them. They
built three with each lighter and after the third the Navy said it was
still too heavy and Grumman said okay, we are not going to build it any
lighter so forget it. So there are aircraft design engineers out there
that may think like me, but only somewhat, I agree. I worked for Douglas
Aircraft and their philosophy was, build it light, and then beef it up
where required later. Thanks,

Bob Lowe

This was essentially how the Navy got out of accepting the General
Dynamics F-111, except they tidied it all up in "wind over the deck"
calculations.
--
Cheers,

John B.

On Fri, 07 Feb 2014 18:16:14 -0600, Richard
wrote:

On 2/7/2014 2:18 PM, Bob Lowe wrote:


Hi - FWTW, I just cut this from a 737 accident report...Engine mounts on
Boeing jetliners are a major safety issue.
I have always maintained that I would make a poor aircraft designer
because my planes would be too heavy to fly. At one time I was a liaison
at the Grumman plant at Calverton, Long Island and it was after Grumman
had been asked by the Navy to design an F-111 version for them. They
built three with each lighter and after the third the Navy said it was
still too heavy and Grumman said okay, we are not going to build it any
lighter so forget it. So there are aircraft design engineers out there
that may think like me, but only somewhat, I agree. I worked for Douglas
Aircraft and their philosophy was, build it light, and then beef it up
where required later. Thanks,

Bob Lowe



That was Ed Heinemann's philosophy.

There were a few problems with the original A-4 Skyhawk as a result.
Mostly systems stuff . . .

These first four aircraft were really challenging. They weighed
some 9800# empty and everything seemed to go wrong on test flights.
During these early flights test pilots discovered that the speed
brakes cracked in a high speed dive, the metal flange alongside the
vertical tail peeled back in high speed runs and the slats tended to
hang up resulting in violent accelerated stalls. In addition, the
oil pressure gage was a simple flip/flop gage, with barber poles the
only indication of pump/oil failure.

On the other hand, once the teething problems were ironed out it was
one hell of an attack airplane.

It was reported that the wing had an infinite fatigue life - even if
flown at full combat weight and max Gs.

But that is fairly typical of most airplanes and the manufacturer
issues a fix. When I worked on DC-3 gun ships in Vietnam there were
still Technical Compliance Orders being issued on aircraft that were
close to 30 years old.
--
Cheers,

John B.

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Yes Jim - I just looked at your link, Ti64...and book marked it as
'Essential'.
And your guesstimation rule is easy to remember. Another thing, the first
time
I saw the engine mounting bolts on a 707 right after it went into passenger
service again I was surprised....As I remember they were three, either 3/4
or 1
inch bolts holding each engine on. Thank you Jim.


Hey John B - You mentioned Puff...I use to watch Puff in action just south
of DaNang in 67-68...maybe we there at the same time. And TO's..I
initiated a few TO's while working for Douglas.

Bob Lowe

--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups

Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Aircraft parts are manufactured and tested to specifications which depend on
their use. So 'aircraft quality' only means that they conform to some
specification and QA processes are in place to ensure that they do.

An 'aircraft quality' bolt may not be any stronger than a typical hardware
store grade one. But you can be fairly certain that they all meet the spec.

--
Paul Hovnanian
------------------------------------------------------------------
If your only tool is a hammer then every problem looks like a thumb.

On Sat, 08 Feb 2014 21:18:02 +0000, Bob Lowe
wrote:

replying to Bob Lowe, Bob Lowe wrote:
Bob Lowe wrote:

Yes Jim - I just looked at your link, Ti64...and book marked it as
'Essential'.
And your guesstimation rule is easy to remember. Another thing, the first
time
I saw the engine mounting bolts on a 707 right after it went into passenger
service again I was surprised....As I remember they were three, either 3/4
or 1
inch bolts holding each engine on. Thank you Jim.


Hey John B - You mentioned Puff...I use to watch Puff in action just south
of DaNang in 67-68...maybe we there at the same time. And TO's..I
initiated a few TO's while working for Douglas.

Bob Lowe

I arrived back in the States and the first TV I saw had pictures of
5th Special Forces fighting their Tet '68 offensive about a block from
the house I had lived in, in Nha Trang :-)

But actually the Gunny Birds were a horror to maintain. We had one
ship that after a couple of missions the mini guns started to "list".
The "Tin Benders" lifted a panel in the floor and the formers and
brackets that supported the floor were corroded and failing. We ripped
the floor out and re-built it but that bird was out for nearly a
month. I have no idea where the A.F. got those things but one, I
checked, was as old as I was :-)

The squadron's brag was that if we got there before Charley had gotten
through the wire then it was a done deal - we never lost a camp or a
fort. I used to eat in the 5th S.F. NCO mess as a guest based on that.
--
Cheers,

John B.

On Sat, 08 Feb 2014 17:11:51 -0800, "Paul Hovnanian P.E."
wrote:

Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Aircraft parts are manufactured and tested to specifications which depend on
their use. So 'aircraft quality' only means that they conform to some
specification and QA processes are in place to ensure that they do.

An 'aircraft quality' bolt may not be any stronger than a typical hardware
store grade one. But you can be fairly certain that they all meet the spec.

In the airplane fixing business "Aircraft Quality" is a meaningless
term, or at least I never saw the term used in more then 20 years of
working on the things. What would be specified was something like
Bolt, AN 64-23, fiber self locking nut, AN 23-24, washer, AN
23-405.\, or maybe Bolt, internal wrenching, P.N. 23-12345.
--
Cheers,

John B.

On 2/9/14, 4:00 AM, John B. wrote:
On Sat, 08 Feb 2014 17:11:51 -0800, "Paul Hovnanian P.E."
wrote:

Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Aircraft parts are manufactured and tested to specifications which depend on
their use. So 'aircraft quality' only means that they conform to some
specification and QA processes are in place to ensure that they do.

An 'aircraft quality' bolt may not be any stronger than a typical hardware
store grade one. But you can be fairly certain that they all meet the spec.

In the airplane fixing business "Aircraft Quality" is a meaningless
term, or at least I never saw the term used in more then 20 years of
working on the things. What would be specified was something like
Bolt, AN 64-23, fiber self locking nut, AN 23-24, washer, AN
23-405.\, or maybe Bolt, internal wrenching, P.N. 23-12345.


Yes, agreed. That 'Aircraft Quality' statement always equates to some
snake oil marketer peddling off crap.

Erik

On Sun, 09 Feb 2014 13:53:14 -0800, Erik wrote:

On 2/9/14, 4:00 AM, John B. wrote:
On Sat, 08 Feb 2014 17:11:51 -0800, "Paul Hovnanian P.E."
wrote:

Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Aircraft parts are manufactured and tested to specifications which depend on
their use. So 'aircraft quality' only means that they conform to some
specification and QA processes are in place to ensure that they do.

An 'aircraft quality' bolt may not be any stronger than a typical hardware
store grade one. But you can be fairly certain that they all meet the spec.

In the airplane fixing business "Aircraft Quality" is a meaningless
term, or at least I never saw the term used in more then 20 years of
working on the things. What would be specified was something like
Bolt, AN 64-23, fiber self locking nut, AN 23-24, washer, AN
23-405.\, or maybe Bolt, internal wrenching, P.N. 23-12345.


Yes, agreed. That 'Aircraft Quality' statement always equates to some
snake oil marketer peddling off crap.

Erik
I live in the Seattle area where everybody either works at, worked at,
or knows someone who works at Boeing. "Aircraft Quality" is used
around here a lot. For example, I was in a local bike shop once and
they had a fancy new frame hanging from the ceiling that was "Aircraft
Quality T6" So I asked the guy which alloy the frame was made from and
he tells me "It says right there, T6" . I told him that T6 was a
temper designation, not an alloy. He said then that he knew aluminum
and that T6 was an aircraft quality aluminum alloy. Then he said that
they also had cranks made from "Billet Alloy". Which was also
"Aircraft Quality". I just bought the light I went in for and left.
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Sun, 09 Feb 2014 15:45:08 -0800, wrote:

On Sun, 09 Feb 2014 13:53:14 -0800, Erik wrote:

On 2/9/14, 4:00 AM, John B. wrote:
On Sat, 08 Feb 2014 17:11:51 -0800, "Paul Hovnanian P.E."
wrote:

Bob Lowe wrote:

Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

Aircraft parts are manufactured and tested to specifications which depend on
their use. So 'aircraft quality' only means that they conform to some
specification and QA processes are in place to ensure that they do.

An 'aircraft quality' bolt may not be any stronger than a typical hardware
store grade one. But you can be fairly certain that they all meet the spec.

In the airplane fixing business "Aircraft Quality" is a meaningless
term, or at least I never saw the term used in more then 20 years of
working on the things. What would be specified was something like
Bolt, AN 64-23, fiber self locking nut, AN 23-24, washer, AN
23-405.\, or maybe Bolt, internal wrenching, P.N. 23-12345.


Yes, agreed. That 'Aircraft Quality' statement always equates to some
snake oil marketer peddling off crap.

Erik
I live in the Seattle area where everybody either works at, worked at,
or knows someone who works at Boeing. "Aircraft Quality" is used
around here a lot. For example, I was in a local bike shop once and
they had a fancy new frame hanging from the ceiling that was "Aircraft
Quality T6" So I asked the guy which alloy the frame was made from and
he tells me "It says right there, T6" . I told him that T6 was a
temper designation, not an alloy. He said then that he knew aluminum
and that T6 was an aircraft quality aluminum alloy. Then he said that
they also had cranks made from "Billet Alloy". Which was also
"Aircraft Quality". I just bought the light I went in for and left.
Eric


You could have argued that "T-6" was actually a marine alloy as it is,
so often, used to designate the masts and spars of sail boats :-)
And, I've always wondered about the "billet" designation. The advert
writer could have equally used "ingot" which has, sort of, an
association with gold bars :-)
--
Cheers,

John B.

"John B." wrote in message
...
And, I've always wondered about the "billet" designation. The advert
writer could have equally used "ingot" which has, sort of, an
association with gold bars :-)
--
Cheers,

John B.

I assumed that 'billet' meant the part had been machined from bar
stock instead of stamped or forged.
http://en.wikipedia.org/wiki/Camshaft

jsw

On Sunday, February 9, 2014 7:10:45 PM UTC-5, John B. wrote:


You could have argued that "T-6" was actually a marine alloy as it is,

so often, used to designate the masts and spars of sail boats :-)



Cheers,



John B.

You need to refresh your memory on aluminum alloys. As I remember all the marine alloys are five thousand and something.

Dan

On Sun, 9 Feb 2014 17:32:13 -0800 (PST), "
wrote:

On Sunday, February 9, 2014 7:10:45 PM UTC-5, John B. wrote:


You could have argued that "T-6" was actually a marine alloy as it is,

so often, used to designate the masts and spars of sail boats :-)



Cheers,



John B.

You need to refresh your memory on aluminum alloys. As I remember all the marine alloys are five thousand and something.

Dan
But they will be used in the T6 condition - which is about the
hardest AND toughest an aluminum alloy can be - Solution Heat trested
and artificially aged..

On Sun, 9 Feb 2014 17:32:13 -0800 (PST), "
wrote:

On Sunday, February 9, 2014 7:10:45 PM UTC-5, John B. wrote:


You could have argued that "T-6" was actually a marine alloy as it is,

so often, used to designate the masts and spars of sail boats :-)



Cheers,



John B.

You need to refresh your memory on aluminum alloys. As I remember all the marine alloys are five thousand and something.

Dan

But spars are most often 6061 or 6063. Which just goes to show that
"marine," "aircraft," and "surgical" don't have much meaning when it
comes to materials.

--
Ned Simmons

On Sun, 09 Feb 2014 21:34:50 -0500, wrote:

On Sun, 9 Feb 2014 17:32:13 -0800 (PST), "
wrote:

On Sunday, February 9, 2014 7:10:45 PM UTC-5, John B. wrote:


You could have argued that "T-6" was actually a marine alloy as it is,

so often, used to designate the masts and spars of sail boats :-)



Cheers,



John B.

You need to refresh your memory on aluminum alloys. As I remember all the marine alloys are five thousand and something.

Dan
But they will be used in the T6 condition - which is about the
hardest AND toughest an aluminum alloy can be - Solution Heat trested
and artificially aged..

But not applicable to the 5xxx alloys, which are strengthened by cold
working, not heat treating.

--
Ned Simmons

replying to Jim Wilkins , Bob Lowe wrote:
muratlanne wrote:

"John B." wrote in message
...
I assumed that 'billet' meant the part had been machined from bar
stock instead of stamped or forged.
http://en.wikipedia.org/wiki/Camshaft
jsw


Thanks for all of the info and where to find more...I worked all of my
life in the aircraft field but never with nuts and bolts...I was always in
the electronics part. We did get retrofit 'kits' sometimes but someone
else made them up. The first plane I flew in was a Tri Motored Ford and
the last was a Stearman PT-17 with 70 years in between. My first
operation squadron in the Air Force was made up of B-17's and C-47's and
after that since 66 I worked for NAVAIR and NAESU, sorry for the acronyms.
I don't know about the proper use of Billet 'designation' but I do know
when I worked at the Douglas, El Segundo Plant, truck loads of aluminum
alloy 'billets' would come in every day. I just looked in a reference
book and it says, under Aluminum Types: Class T6, Solution heat-treated
and then artificially aged. Common class. Now I have to find out what is
'artificially aged'. Is this some kind of freezing and warming process?

--
posted from
http://www.polytechforum.com/metalwo...ts-592658-.htm
using PolytechForum's Web, RSS and Social Media Interface to
rec.crafts.metalworking and other engineering groups