On 2/4/2014 10:18 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,

Fasteners will be spec'ed by the manufacturer for the purpose as far as
tensile strength, etc., using a specific set of spec's whether they be
military or internal for civilian aircraft. The "Quality" refers to the
QC pedigree that they meet the standard pedigree and have the paperwork
associated for whatever performance spec is pertinent; it doesn't mean
anything specific regarding what that performance spec to which it
adheres is; that's referred to but not the same thing.

It's like the "N-Stamp" for nuclear-qualified pieces-parts for reactors;
the actual spec's met are different depending on what the reqm't is, the
N-Stamp only assures that it was produced according to the protocol of
documentation and certification and record-keeping required which is far
beyond that of "ordinary" material which may, actually, be of precisely
the same actual functional spec.

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