Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


AN NAS MS Part Cross Reference

AN NAS MS Part Cross Reference

AN NAS MS Part Cross Reference

Many years ago, when I first started in this industry one of the designers gave me a photocopy of a multi-page reference showing AN NAS and MS parts (original source AIMSCO I believe), their supercessions, etc.  I am now trying to compile a Design Manual, and would like to use this as a starting point, updating the supercessions and cross references. But alas my copy is worn and tattered making it unsuitable for scanning and use in the manual.  Does anyone have a relatively clean copy scanned that I could use?  There appears to be a good copy on "Engineers Edge", however, all attempts to contact them and obtain an unlocked/printable version have been in vain.

Your help with this and any suggestions for sources of data for inclusion in the manual are appreciated.


Randall Shelaga AScT
Manager, Technical Operations
DIRAND Aerotech Inc.

RE: AN NAS MS Part Cross Reference


I looked at the Engineers Edge site and one or two of the NAS, MS parts catalogues. Once opened and the PDF file has loaded onto your computer you can save it to a folder on your system. Would that not be sufficient? You should be able to print the PDF file from there.

Hope this helps.


RE: AN NAS MS Part Cross Reference

I've jumped through those hoops....what I need to do is update the information on the drawings (by editing or adding to the existing annotations), which I can do with PaperPort, and then embed the final document into company format.

I am looking at investing some time in this, which should result in greatly reduced workload in the design review cycle.


Randall Shelaga AScT
Manager, Technical Operations
DIRAND Aerotech Inc.

RE: AN NAS MS Part Cross Reference

Have you experimented with OCR (Optical Character Recognition) software?  I'm unfamiliar with PaperPort, so I don't know if this is included.  Some OCR software is less reliable than others, but if you or a colleague is comfortable with a particular OCR package you might have some good results from that.

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

RE: AN NAS MS Part Cross Reference

randwolfe... You’re a glutton for punishment.

1.    I have been working on a similar... but broader… database for several years. There are several aspects to this "project" that have keep me busy sorting/scratching.

2.    To give You a different perspective on parts, I have a few questions [tasks] for You to consider answering. These “simple” questions” are not so simple… and may give You a different perspective on Your parts catalog effort. Four questions/exercises follow…

a.    A catalog has to have a rationale way of segregating parts for easy “finding” [search] by users [designers, etc].

Also, what is Your definition of a “bolt” and a “screw”???
As an exercise, try naming a few bolt styles [bolt style/type influences function].

b.    Parts and materials… clear or murky differences?

What is the difference between a “part” and “finished material”?
Is a shim/filler a part or material”?
Is insulation a part or material?
Are ANDxxxxx extrusions: (a) parts: (b) materials: (c) both: or (d) “raw product” definition?
Is high-temp aluminum foil tape [for on-acft application] a part or material???
Is safety-wire a part or material?

c.    What is the difference between a “part spec”, a “procurement spec” and a “design and usage limitations spec”?

d.    Some parts have multiple-functions… identify a couple…

3.    FYI: There have been numbering system changes over the last few years.  “Standard aerospace parts” have been traditionally listed under the following categories [metric parts have different prefix codes]…

    A-A-*  [Commercial Item Description]
AN*  [Army Navy]
AND*  [Army Navy]
AS*  [SAE]
Fed-*-* [Federal Govt]
MIL-*-*    [also, M* has been used for certain “MIL-*-* part-numbers]  [Military]
MS  [Military]

These specs have recently been pared down to the following “base specs”… although the actual part numbers MAY have not changed [“part numbers remain…”]

AS [included certain AN*, MIL-*-* and MS* parts]
NASM [included certain AN*, MIL-*-* and MS* parts],  

Regards, Wil Taylor

RE: AN NAS MS Part Cross Reference

OK... it looks like my comments didn't go over as expected.

Here's what I MENT to ask "randwolfe" to do as a "mental exercise".

For bolts mechanical & structures engineers will think like this...
NOTE: NOT considered in the following discussion are non-structural [light duty] “screws” or “cap-bolts” with very-long or full-threaded shanks intended for simple fastening and mechanical parts installation/clamp-up.
BASIC TYPES: "Conventional" threaded bolts, threaded lock-bolts [Hi-Lok Style], Swaged-collar Lock-Bolts [Stump & Pin-Pull, sometimes called "rivets" in the specs], Jo-Bolt style Blind-Bolts [threaded core-pin to pull swaged-collar] and Pin-Pull Lock-Bolts [deformed shank, formed-bulbed-tail].  

RATING: Shear, Tension, Shear-Tension, nominal-use or high-reuse/reinstallation and fatigue.

STRENGTH: 75/90/125/145/160/180/200/220/240(+)-KSI [FTU and/or FSU]

ALLOY: aluminum, brass/bronze/monel/Cu-Be, steel, CRES, A286, Titanium, Inconel 718, MP35, etc,

FINISHES: bare, passivated, phosphated, cadmium-plated, nickel-cadmium plated, chrome-plated, aluminum coated. Note: Cad-plated parts most-likely have post-plating chromate treatment.

TEMPERATURE AND ENVIRONMENT: NOTE... Materials, finishes and locking-patch element material dictate temperature use limitations, typically: Cryogenic [below -100F], -65F [nominal minimum] up-to +250F, +450F, +600F, +900F, +1200F, etc. Dissimilar material interface and specific environments must be considered, such as propulsion VS mechanical VS fixed-structures. Also must consider affect on electrical conductivity... especially where bonding and grounding for EE-EL systems and/or lightning-strikes are required.

Protruding Head Styles: none [Hi-Lok Style], Intrnl Hex, Hex, Hex-domed, 12-Pt, spline, W/WO shoulder washer, tension or reduced shear head, low/nominal/deep “height”.

Flush Head: Tension [full depth], Shear [reduced depth], Domed-Flush, 81/100/120 deg CSK angle and various internal drive-recess styles such as None [HL style], Stndrd-X, Offset-X, Dovetail, etc…

Head-to-shank fillet-radius treatment [forged/machined, cold-rolled and/or ground/polished] and fillet-radius size are affected by head style and performance requirements: IE: small/ground/polished fillet for shear rated or Large/rolled/polished fillets for tension/fatigue rated.

Shank style: NAS518 nominal and nominal-oversize diameters, NON-NAS518 diameters, straight-shank or tapered-shank [IE: Taper-Lok style]; and stepped [shouldered]

Threads: long-thread [~1.7xDia long, +/- 0.3xDia], for tension rated nut &/or good grip-length allowance, or short threads [1xDia +/- 0.3xDia] for light-weight [thin] shear nuts. Thread spec & quality, IE: fine, coarse, rolled, ground, proprietary style, etc… Note: for Hi-Loc style there will be an internal Hex-drive in the thread-tip.

OH Yeah… almost forgot the locking features(?): “None” [plain bolt], drilled-head and/or drilled-threads [for lock-wire or cotter-pins]; added patch-locking element embedded in the threads; and self-locking bolts [IE: positive pin-ball-lock or ring-lock impedance].

Probably missed a few minor aspects... but I think this covers the major categorizing elements

Now: anyone care to try a similar categorizing exercise for “Washers”, “Nuts”, “Pins”, etc??????

Regards, Wil Taylor

RE: AN NAS MS Part Cross Reference


NAS, MS and AN hardware standards are all being phased out. The documentation for these standards are now typically labelled "inactive for new design.....superceded by....". The US military procurement has adopted a COTS (Commercial Off The Shelf) mentality and no longer wants to spend their money maintaining hardware documentation.

The current standards in the US for aircraft/aerospace hardware are usually prefixed "AS...", the custodian for these standards is typically the SAE, and you can purchase  "AS" hardware specs from the SAE:


You can also purchase specs from Global/IHS:


Most large commercial aerospace companies (like Boeing) purchase hardware produced to their own internal QC specs (Boeing spec hardware usually has a "BAC" prefix). These companies spend a large amount of money developing and maintaining their hardware specs, and thus treat the information as confidential/proprietary. If you somehow come into posession of another companies' hardware specs, I would advise you to not incorporate that information into the documentation you are preparing, regardless of how tempting it may seem.

Do the right thing and pay IHS or the SAE for the documentation.

Good Luck,

RE: AN NAS MS Part Cross Reference


I both STRONGLY agree and disagree with You.

Yes, the Military is pretty much out of the parts spec buisness. But, virtually all these specs were transferred to AIA [NASxxx and NASMxxx] or SAE [ASxxxxx] with a "relabling". In a few cases, neither group wanted the spec and they were declared "inactive"... but valid for procurement.

"NAS" and "NASM" specs are established and maintained by the AIA. "AS" specs are established and maintained by SAE. These specs ARE NOT going away.

The AN, MS and MIL-* Specs You refered to as "superceded" are generally listed as superceded by  NASMxxxxx [instead on AN, MS, MIL-* etc], or ASxxxxx... with the original number used in some shape/form. When You go to the NASM, the fine print says "part numbers remain "AN", MS", MIL-* [or maybe M*]... so very little changed there. In the AS specs the "ASxxxxx" [AS followed by original spec number] is general translation of the old PN. In many of these specs the old [AN, MS, MIL-] P/Ns are compared to the new "AS" P/N.

Company hardware Specs often duplicate [and sometimes refer directly to] equivalent HL NAS or AS specs... The primary differences are in the procurement spec to "insure quality" [reliability]. HOWEVER, the fastener quality act [1990s] essentially mandated source procurement and traceability for all parts installed on aircraft... which had been the BIG quality issue on non-company parts. Now the differences between NAS and BACB30XX parts are mostly insignificant... except for cost... which can be a premium for company-specific parts.

My DoD customer insists that "generic" [NAS, AS, etc] parts be specified along-with any company specific parts, wherever feasible.. or that the generic fastener substitution documents/drawings allow this directly. This controls cost and improves availability for them. With the FQA in the background, we do not believe that this poses an unacceptable risk. In fact, my company has been adding many of the later generation NAS and AS parts back into the "acceptable for use by..." listing.

Regards, Wil Taylor

NOTE: the DoD is not yet out of the material business... many material MIL-*-** documents were made into MIL-PRF-** [performance spec] and MIL-DTL-* [Detail spec] documents... because DoD was still the locical "owner".

Regards, Wil Taylor

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close