AN-QQ-S-757
AN-QQ-S-757
(OP)
Hi all;
I have been asked to find a Stainless Steel to AN-QQ-S-757. The spec is obsolete (we are restoring a P-47 Thunderbolt WW2 fighter aircraft) and we have not been able to find anything via SAE. We think that 321 may be an acceptable substitute but we need some way of qualifying this. Any gurus out there on old specs?
Thanks in advance!
I have been asked to find a Stainless Steel to AN-QQ-S-757. The spec is obsolete (we are restoring a P-47 Thunderbolt WW2 fighter aircraft) and we have not been able to find anything via SAE. We think that 321 may be an acceptable substitute but we need some way of qualifying this. Any gurus out there on old specs?
Thanks in advance!





RE: AN-QQ-S-757
RE: AN-QQ-S-757
RE: AN-QQ-S-757
RE: AN-QQ-S-757
According to those sites the material is CRES 321 per AN-QQ-S-757 part. However it may be that more stainless steels types are included in this spec.
http://fas
http:
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RE: AN-QQ-S-757
I have a suspician... but I need-to-know...
Is the part made from sheet, plate, bar, etc?
Also... what is the title and function of the part?
Regards, Wil Taylor
RE: AN-QQ-S-757
Does this help?
RE: AN-QQ-S-757
My dad built a small all metal homebuilt [T-18] when I was a kid (1967--1972). The designer had (2) options for the firewall and attaching structure [brackets, clips, etc]:
301/304 CRES Sheet 1/8-Hard
or
galvanized steel sheet, next gage thicker than CRES Sheet.
My dad chose to make the firewall and some stiffeners/brackets from Galvanized steel.
I thought this was very odd... and asked the designer [John Thorp] Why: he said the firewall and connecting parts had to survive the 15-minute fire just once... long-enough to get the bird safely on the ground.
Apparently use of galvanized steel sheet was VERY common in older aircraft for reasonable toughness/durability/fire resistance... and co$t $aving$.
Regards, Wil Taylor
RE: AN-QQ-S-757
RE: AN-QQ-S-757
Regards, Wil Taylor
RE: AN-QQ-S-757
RE: AN-QQ-S-757
For WW-II throw-away fighter acft**, a gage-thicker Galv Stl would work "OK" relative to more-precious CRES.
** many never reached 500-hrs TT... and high time fighter-trainers would have ~1500-hrs TT... when scrapped.
Today's design standards are vastly different from +50-yrs-ago design standards.
Regards, Wil Taylor