Fastener strength

[RMPE]

What is the strength for a hex bolt fastener with markings A,F,X and O in the center. It is in an aircraft hangar so it may be an aircraft bolt.

 

[yates]

With a marking of that type, I rather think it fell off the hangar than off of an airplane ! Maybe someone else can shed light on this marking but it doesn't look like an aircraft bolt to me.

 

[boo1]

Take a look at MIL-STD-1291. It is available at the ASSIST website, like all the other military specifications.

http://assist.daps.dla.mil/docimages/0001/59/31/1291A.PD3

With a quick glance, I don't see the symbol you described, but perhaps a closer inspection will find it.

Appear to be an AN (AN 3-20)standard steel type with manufactures marking

For a good marking pics see:

http://www.vikingbolt.com/sub_pages/specifications/spec_pages/ident_markings/index.htm