MP E marked bolts?

[IPSC_GUY]

I know MP is Magnetic Particle inspection, What does the "E" designate?

IPSC_GUY
SIERRA II ALPHA

[IPSC_GUY]

are you sure it's not a MPF... F with a line under it?

MPF is FN


Ahhh Upon closer inspection that is exactly what it is,

Thanks

IPSC_GUY
SIERRA II ALPHA