What would be a sufficiently robust way to rethread a hole for a grub which needs to be very tightly fastened?
I have a tilt and slide patio door. The bottom fixtures are secured together by a dowel bar to help prevent the door twisting.
The thread in the hole for a grub which holds the dowel bar in place has sheared off when tightening the grub.
It turns out that the grub needs to be very tightly screwed against the dowel as the door has a tendency to twist at the base as the door tilts (possible installation fault as either frame or door are not quite plumb). The door gets used heavily as this is the only way my dog can get into my back yard from the house.