I am designing an item with 4 screws M6 fastened on 4 through holes obtained on aluminum bores (height = 12 mm) at the respective ends of a flange.
I am evaluating the category of captive screws since for handling reasons I would like to tight the screws on the holes so as to keep them fixed, even e.g. if I turn the item upside down.
Since the holes are through and not threaded, I should use a fastening sysemt such as a fischer plug system (like wall plugs), but the bores are too short (12 mm) for such plugs. I would like to avoid complications such as cotter pins and other systems difficult to remove after final assembling of the item.
Can you suggest me some commercial screws or systems that help me in this way?
Thank you very much for your help.