With regard to aircraft hardware vs hardware store:
AN bolts (such as an AN4) are garden variety aircraft bolts
AN bolts (such as an AN4) made of CRES (corrosion resistant steel) (stainless) are designed to meet the exact same specs.
All AN Bolts meet minimum Tensile Strength Values of 125,000 PSI
Commercial Grade 8 Bolts Have a Comparitive Strength of 150,000 PSI
Commercial Grade 5 Bolts Have a Comparitive Strength of 120,000 PSI
Dropping to 110.000 PSI for Diameters Greater Than 1-Inch
Commercial Grade 2 Bolts Have a Comparitive Strength of 70.000 PSI
Dropping to 60.000 PSI for Diameters Greater Than 3/4"
The reason I bring this up is that "hardware store" 18-8 stainless or even marine stainless can be as low as 20,000 PSI depending on quality. Though it is much more typical to see hardware store stainless at 65,000 PSI tensile strength.