SI Aircraft Fasteners 2

[i278]

Hello all,

This seems a rather ignorant question, but I can't seem to find any information on my own; and so...

Is there a system running parallel to AN/MS/NAS for metric fasteners? I'm sure that some of the more recent NAS material has some metric sizing, but I don't know how comprehensive a selection it is.

Just as important as the fasteners, of course, would be publicly-available and FAA/JAA/CAA etc.-accepted allowable material (a la MIL-HDBK-5).

It may be that I can't find anything because it doesn't exist--but it seems odd that Europe, Asia, and Australia would still be bashing MS20470s!

Any pointers?

 

[vonlueke]

As for as the NAS fasteners, their metric parallel is all the "NA" fasteners (NA0067, NA0113, etc.).

To get an NA spec for a particular part number, get it from anywhere where you can get the NAS spec sheets. To find all NA part numbers and specs, search your specification database with search strings like "NA*" and "metric" and "bolt" or "washer," etc. Notice the asterisk (wildcard) after NA; but "metric" filters out NAS hits.

For example, perhaps try

http://standards.nasa.gov/

(it appears the public can order one nontransferable copy of spec on-line, but for a charge per spec; follow instructions therein; hope they're not overcharging). Or, to at least see spec names, try the above search string suggestions at

http://stinet.dtic.mil/str/dodiss4_fields.html

. Or, perhaps try

http://astimage.daps.dla.mil/quicksearch/

(slow, and I frequently can't get the search strings to work right, and frequently doesn't have many documents full text on-line). That takes care of the NA fasteners. Regarding the others you mentioned, especially commercial-grade or publicly-available metric fastener specs (especially on-line), metric material specs, etc., I hope someone else can give us tips on that, including the best tips for finding the specs publicly-available, full-text, on-line. And where's a good on-line site for looking up dimensions of standard metric structural member shapes?

And the metric fastener dimensions and properties can be found at, e.g., the SARL at

http://euler9.tripod.com/bolt-database/

. (The pop-ups are killed if you turn off javascript, called "Scripting" in IE, in your browser options.) Even though NA properties are not included in that commercial fastener material strength properties list therein, many of the NA bolts are 1100 MPa UTS, 655 MPa shear (just like most NAS bolts, except NAS1003). Good luck.

 

vonlueke: Thanks for the tips. Correction: For the public to at least see all NA spec names, use your search tips with the

http://standards.nasa.gov/

site you mentioned, not the other two spec links. The other two links cover military specs (MIL, MS), I think. NAS and NA are not military; they're private sector--and therefore I guess not many of them are on those two military spec links you listed (?). Whereas the NASA link covers all specs worldwide, I think.

Also, the strength you mention on NA fasteners implies you are probably referring only to the A-286 material option. Some NA part numbers also have non-A-286 material options. Of course read the fine print on each spec to ascertain the fastener strength for the material option you're calling out. Thanks.

 

[vonlueke]

Thanks, pmyy18, for clarifying that strength value I mentioned. It's for A-286, and sometimes a few other materials. Like you said, always read the spec.

You're correct in saying you can do the NA search on

http://standards.nasa.gov/,

but as I mentioned, you can at least see the NA spec names at the second URL, also. I mentioned the search tips in a general way, admittedly not clearly. Here's an example of what you enter into the search fields at the first and second links, respectively. Notice the difference in booleans.

In

http://standards.nasa.gov/

(after you create your login ID). This system uses a default boolean of AND.

    Document number:  na*
     Title keywords:  metric screw

In

http://stinet.dtic.mil/str/dodiss4_fields.html

. This system allows booleans; default boolean is OR.

   DODISS ID number:  na*
              Title:  metric and screw

In both cases, "metric" filters out all NAS. In addition to "screw," shown above, also perform separate searches for "bolt," "nut," "washer," etc. Hope this helps.

 

Thanks. I got it to work now.

Also, we should clarify, even though most NA A-286 bolts have the strength value you mentioned, a few NA or NAS bolt part numbers, even if A-286, might not, so always read the individual spec. By the way, that ultimate shear strength you mentioned should be 660 MPa (not 655). Thanks.