Aircraft Fastener Properties?

[Wittenborn]

Is there a specific reference for fastener properties and allowables? Primarily AN type steel bolts, and corresponding nuts, washers, etc. I am looking for Military specs for properties...

I am looking through the ASSIST Online site, and am not having any luck with their primitive search engine. Searching for "bolt" turns up 1000+ hits, most of which are obsolete.

Any help will be much appreciated!


Regards,
Grant
Aerospace Engineer

 

[TVP]

Most of the government controlled documents have been cancelled and replaced with NASM standards. You can still obtain the original standards (AN or similar) using the ASSIST site, and review the materials and mechanical properties that are specified. Also, MIL-HDBK-5 has information on property allowables, and it too is available on ASSIST.

 

[Wittenborn]

Thanks TVP,

Do you know where I can find the NASM standards?



Regards,
Grant
Aerospace Engineer

 

[hombre]

Grant,

Look in Chapter 8 of MIL-HDBK-5 under threaded fasteners. The shear and tension allowables are based on the shear and tensile stress of the fastener, respectively.

For example, the AN3 bolts are 95 ksi shear and 125 ksi tension. Therefore, the allowable shear load is 2690 lbs. and the allowable tension load is 2255 lbs.

Look in the AN spec for the material strengths.

Todd

P.S.

Rock Chalk Jayhawk!

 

[Wittenborn]

Thanks Todd,

I am looking through Ch 8 of MIL-HDBK-5J, and I think what I'm looking for is the AN specs, or according to the post above, the NASM specs. I do not believe they are listed on the ASSIST website...

Rock Chalk!

Regards,
Grant
Aerospace Engineer

 

[Sparweb]

Grant,

I find it odd that you're asking this question, given where, and for whom you work....Anyway...

Standards developed for the military (AN/MS/MIL) are public-domain information (mostly). NAS is a series of specifications developed by the Aerospace Industries Association of America. As such, the information is privately controlled, and must be purchased from them. The cheapest way to get a complete list is on Microfiche (from ATP, maybe), but if you only want a few numbers, nothing beats a PDF ordered from their website:

http://www.techstreet.com/aiagate.html

You usually pay about 5 US$ per page or so.

BTW: I've found a bit of data regarding helicopter moments of inertia, but nothing that I can properly substantiate, yet.


"Simplicate, and add more lightness" - Bill Stout
Steven Fahey, CET

 

[Wittenborn]

Thanks Steven,

Actually, we have all of this information for when we were developing our software. However we developed that part of the software nearly 10 years ago, and our current data is obviously obsolete. Our last version of MIL-HDBK-5 is "G", of which they are now up to "J".

We are now doing some detailed design work that is requiring our use of current data. We could have purchased this doccument from several sources, but what I really wanted was the .pdf. As you probably know, this document is about 1,700 pags long, making it costly to print, but if you have the electronic format, you can print only the pages you need...

Being the first time we have needed this information, I did not know where to look for an electronic format.

Anyway, on the rotorcraft properties, you may want to look for publications from Bell Helicopter, although it may be tough to get them to let you have it.

Are you looking for data on anything in specific on a helicopter?





Regards,
Grant
Aerospace Engineer

 

[Sparweb]

To help you stay current, keep an eye on this:

thread2-85431

The FAA will be taking over from the military for civilian aircraft materials. It's a good question how long Mil-Hdbk-5 will be updated and available to the public after that.


"Simplicate, and add more lightness" - Bill Stout
Steven Fahey, CET

 

[Wittenborn]

Wow! That's news to me! Thanks!

It appears that others were not aware of this either.



Regards,
Grant
Aerospace Engineer

 

[tbuelna]

Grant:

These guys have every standard/spec on the face of the earth:

http://global.ihs.com

It's expensive, but they are the best document service available.

Regards,
Terry

 

[Kiwikid]

Source:

http://aar400.tc.faa.gov/Programs/AgingAircraft/Structural/Aging Aircraft 2003 MMPDS PaperV3.pdf

Abstract
This year, 2003, marks the first year of publication of the Metallic Material Properties Development
and Standardization (MMPDS) Handbook and the final year of publication of MIL-HDBK-5. For
this year only, MMPDS-01 and MIL-HDBK-5J will be technically equivalent. In the spring of 2004,
when the 1st Change Notice of MMPDS-01 is published, MIL-HDBK-5 will be designated
noncurrent and MMPDS will become the only government recognized source in the U.S. of
published design allowable properties for commercial and military aircraft structures and
mechanically fastened joints. In this way, the 65-year legacy of MIL-HDBK-5, and its predecessor
Army-Navy-Commerce Handbook 5, will be maintained.

You can download the new MMPDS doc here for free

http://www.tc.faa.gov/its/worldpac/techrpt/ar-mmpds-01.pdf