7178-T651 Mil-Hdk-5D Material properties thread2-188255 1

[OnAQuest]

Could someone please let me know, in order of preference, how to:
1) download a pdf of Mil-Hdbk-5D.
2) download a pdf of the mechanical properties data for 7178-T651 Extrusion from Mil-Hdbk-5D.
3) reply with the properties (especially the yield and ultimate bearing stress allowables for 1.5 & 2 e/D).
Thank you

 

[OnAQuest]

I appreciate the information about wandering Mil-Hdbk-5 values. Once years back I talked with a person that was on the comittee that decided what got published in the Mil-Hdbk-5 and if the data met the criterias. He had said that they had never published data that was later found to be non-conservative and that they were quite proud of that. I don't have any reason to doubt what he said especially knowing of his position and reputation. Maybe wandering data doesn't necessarily indicate that the old was non-conservative, just varying levels of conservatism?

 

[WKTaylor]

Onaquest...

In the the mid 1980s I was able (privilaged) to attend several MIL-HDBK-5 comittee meetings as the sole USAF-ALC rep non-voting observer [NOT same as voting AFMC/ASD/AFWAL reps]. Coincidentally most of the voting members were also MIL-STD-1312 and MIL-STD-1515 (fastener) comittee members who discussed related work on-the-side.

What impressed me the most was the massive use of statistics to derive "the simple numbers on the tables". Also, all voting members were acutely aware that as test-sample populations increased, so did the overall confidence in the derived data. Problems with data accuracy were often evident as material fabricators (ALCOA, ALCAN, KAISER, etc) submitted "spec" qualification test data... and the data variations affected the statistically derived "simple numbers on the tables".

In "extreme materials", such as 7178, the allowables varied remarkably over time (usually downward).

In more stable/popular materials properties such as 2024, 7075, etc... A and the B basis allowables have "generally" migrated upward from "S" [spec] basis allowables... all because manufacturers learned the nuances of alloying, heat treating, forming, straining (sheet, plate, extrusion, forgings) etc... the material for optimum/stable mechanical/physical properties (and usually improved SCC & corrosion resistance... etc).

Regards, Wil Taylor

 

[OnAQuest]

The following link has a means of getting the P&W Handbook. I excerpted from the link the primary contact means below:

http://www.airliners.net/aviation-forums/tech_ops/read.main/93610/

"OKAY
Here's the latest from P&W

The Aeronautical Vestpocket Handbook can be purchased from P&W Technical Publications at $36.00 each. (Note: The Helpdesk had mistakenly quoted you the 2003 price).

Please fill out the attached form and mail it with a check or money order made payable to Pratt & Whitney to the following:

Pratt & Whitney
Attn: Sandra Parker
M/S 132-30
400 Main Street
East Hartford, CT 06108

Regards,"
Not free, but $36 isn't bad.
Dave

 

[MNLiaison]

OnAQuest

see attached. Disclaimer: poster does not assume any liability arising out of the application or use of the subject material data. The user assumes all responsibility for the use of the provided information.

Regards

 

[OnAQuest]

MNLiaison-
Thank you very much for the information. This has been quite a task. I understand that this particular alloy is bit of a wandering target and will make this understood to my peers. Fortunately our usage is such that we generally only need to show that it has reasonable strength properties.
Thanks again
Dave

 

[monkeydog]

A star to MNLiaison for not throwing anything!!!!

 

[OnAQuest]

"Not throwing anything"? What does that mean?

 

[rb1957]

well how many of us have kept a copy of 5D ?

 

[OnAQuest]

Gotch ya.