The mysterious disappearance of CRES321 in MIL-HDBK-5J 1

[JohnnyEnglish]

Hello all,

This question could sit in many a forum, so I'll put it here and see what happens.

In the austenitic stainless steels section of MIL-HDBK-5, Table 2.7.1.0(b), reference to CRES 321 has been omitted in rev J (i.e. AR-MMPDS-01). It was originally included in H. There is no rev I.

I have not purchased any later version than AR-MMPDS-01 (which is available for free), and identical to MIL-HDBK-5J. It currently sits at -04.

Does anyone know why this difference might be?
Has it been reinstated in later versions of the MMPDS?

321 is still referenced in the ensuing temperature dependent curves of the both versions.

As an aside, does anyone know if the FAA has adopted MMPDS as the official source for allowables? Judging by this rather old link:

http://airportaircraftsafetyrd.tc.f...uctural/Projects/Std for Data/MMPDS/MMPDS.htm

it seems both are acceptable.

Thanks for your time.

JohnnyEnglish.

 

[rb1957]

i don't think that MMPDS supercedes Mil Hdbk 5, in the way that "Mil Hdbk 5 is unreferencable". MMPDS may well be preferred but the data in Mil Hdbk 5 is still good and IMHO still referencable.

 

[TVP]

JE,

The answer to your question, "Has it been reinstated in later versions of the MMPDS?" is yes. The following is Note e from Table 2.7.1.0(b) of MMPDS-04, which is the replacement for MMPDS-01:

e Properties for annealed (solution heat treated) condition also applicable to AISI 301 plate and to AISI 302, 303, 304, 321, and 347 sheet, strip, and plate, supplied to industry specifications.

Note e appears in the same location as Note a from MIL-HDBK-5H.