Reducing screw hole size in Aluminium frame

Norman_Castle

Try multi strand electrical cable. Strip the plastic outer, put the end into the hole, screw into the hole then cut off the excess if needed.

Ainsley1

Can another type of screw be used, such as a threaded screw?

If so you can buy things called rivnuts. These are a cross between a rivet and a captive nut with threaded inside to match a screw. Typically used on blind holes on aircraft bodywork but should work just as well on an aluminium window frame.
You can then just screw into it and come in various sizes and possibly a 4 or 5mm thread size would be suitable?

Generally designed to work with a rivet puller but they can be pulled by making up something similar from a bolt and a few nuts/washers.

richardw

Thanks for all of your suggestions.
I wrapped some lengths of fuse wire along the length of the screw with smaller diameter fuse wire, this was at the head end of the screw. This seems to have worked and saved a lot of money.