I need to determine a safe working load for the tensile strength of this connection and its giving me trouble. Any tips out there? Dave Wallace and then there is the question of torque so as to not damage the aluminum.
You might get better results drilling a pilot hole and then using a #17 self-tapping screw. It has a smaller head ( good for appearance ), the body is thicker than 1/4", it will enlarge the hole to the root depth of the screw which also tends to make the material slightly thicker there, they are available in SS, I've screwed many thousands into 6061-T6, the Aluminum Association has recommended hole sizes but trying one out for you situation would be best.