Something I haven't seen much discussion of is the proper clearance between a bolt and its hole in aircraft structures. In my day job (designing production machinery) the standard clearance hole is 1/32" (.031) over the nominal bolt size to allow for tolerances and adjustment. But in aircraft the norm seems to be nominal size reamed holes? That can make for an awfully tight fit... in the case of an AN3 bolt the diameter is .186-.189, so a bolt reamed to the nominal 3/16 (.1875) may not accept a bolt on the high side. Of course #10 is really .190 nominal size so that matches all the other AN sizes which are mostly .001-.004 under nominal.
Then once the structure is painted, I presume standard practice is to ream the holes after painting to remove the paint so the bolt fits... leaving no protection on the metal inside the hole?
Then once the structure is painted, I presume standard practice is to ream the holes after painting to remove the paint so the bolt fits... leaving no protection on the metal inside the hole?
