On 2/4/14, 8:18 AM, Bob Lowe wrote:
Hi again- Apparently there is no standard 'Grade' for Aircraft hardware
such as bolts and nuts, only Aircraft 'Quality'. Does anyone know of any
'Standards' for this 'Quality'? The best that I can determine is that
each manufacture of Aircraft Quality Hardware have their own standards and
are not made to any 'Industry' standards. I have found out that some
manufactures will not even give a PSI rating for their nuts and bolts,
only stating that they are of 'Aircraft Quality'. Can anyone put more
light on this?
Thanks,

There are strict standards... You see that 'aircraft quality' BS
statement thrown around all the time by marketers.

Only have a few seconds right now, but Google 'AN hardware' for a start.
Note that the vast majority of aircraft threaded fasteners are fine thread.

There are many special fasteners used in aircraft as well.

Erik