NAS 4002 Fastener Tensile and Shear Testing Thread Pitch Area at max. Dia.

[gfthelen]

Hello All;
Not sure this is the place for this question, but....
For this NAS 4002 Spec, Fastener Testing, Table III shows the Nominal Thread size and TPI, the Nominal Size (IN.) and the Thread pitch area at Max Dia.
Then the values for Min Tensile for Types I, II and III.
Is there a formula for this UNJ stress area of the fastener?

The standard F-606 Area Calculation is NOT correct for this sample. This formula uses the Thread Pitch Dia. in the equation. Would like the formula so I can direct calculate the area in place of a look up table to find area.

Thanks for your help and I have attached the Page for this table.
Regards,
Greg Thelen

 

[WKTaylor]

gfthelen...

ASTM F606 STANDARD TEST METHODS FOR DETERMINING THE MECHANICAL PROPERTIES OF EXTERNALLY AND INTERNALLY THREADED FASTENERS, WASHERS, DIRECT TENSION INDICATORS, AND RIVETS... is generally speaking useful for industrial, mechanical, common fasteners... however... aerospace fasteners are in 'another category all-together'.

For aerospace fasteners [IE: controlled by procurement specs <<examples, only>> NAS4002, NAS4003, NAS4004 and NAS4008], the following documents are valid/applicable...

NAS1348 FASTENERS - RECOMMENDED TENSILE STRESS AREAS FOR - EXTERNAL THREADED

AS5054 AREAS FOR CALCULATING STRESS OR LOAD VALUES FOR EXTERNALLY AND INTERNALLY THREADED FASTENERS

NASM1312 FASTENER TEST METHODS
NASM1312-1 FASTENER TEST METHODS METHOD 1 – SALT SPRAY …
… THRU...
NASM1312-32 FASTENER TEST METHODS METHOD 32 BARREL NUT TEST

BE ADVISED... over-simplified… the ultimate load [tensile/shear] for each type fastener depends on manufactured head, shank/threads/tail [style, length], installed nut/collar strength/stiffness and installation pre-tension/torque... or fastener tail formation... and a whole bunch of other related factors... such as hole-size, joint stiffness/relaxation, etc... etc... etc...



Regards, Wil Taylor
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