Originally Posted by xcflyn
Good idea. It almost looks like he could just go about 1/8" thicker in material. Those bolts are not sticking out the bottom by a thread even. Maybe mill the dia of the hole and use a good bottom tap? May save the machining of the inside if he can just be a little thicker in material ? Guessing the material is already .250+"
I don't know what the specs are for threaded fasteners in plate aluminum, but for rivets in sheet aluminum, Boeing specifies that edge margin is 2.5x the fastener diameter. That's why I picked that number. I would guess that he needs at least the diameter of the fastener of undisturbed metal between the bottom of the hole and the bottom of the screw boss.