If you have a 6mm x 1.0 X 28 mm footstrap screw (the older shorter ones) it's a good idea to put the soap
(either liquid or a bar of bath soap) on the 6mm screw an run it in approx. 2/3 of the way.
Do this on all the FS insert holes you intend to use.
Then put soap on the 7 mm x 1.0 x 32 mm new style footstrap screws and they will go in much more easily, and will last much longer.
You are putting some threads in the holes with the 6mm screw, sort of like tapping the hole.
Oh, DO NOT use any sort of power tool on the footstrap screws!
Use a good quality # 3 Phillips screwdriver... by hand.
Use of power tools creates too much heat and friction and can destroy the holes in the inserts permanently.