I have a stripped screw on a Head Binding into a Speedplate.
What is the proper fix?. The screw is ok, just stripped out in the plastic plate.
I do not have the best cure for you. However I experienced the reverse on the same Head/Tyrolia Speedplate Plus 13 plate with a screw that stripped, slipping only at the tighest point. The screw looked good to the naked eye. I thought the plate hole had stripped but a new bindings screw of the proper/ same size fixed it. Good luck.
Using a larger screw or a Helicoil are the "correct" method. The quick and dirty method is steel wool and epoxy. If you are concerned about rust use bronze wool and epoxy. Fill the hole with the wool and epoxy and insert the screw.
The outside of an insert is essentially a screw. Why on earth would you advise somebody to hammer something threaded into anything.
I have only put these into skis- not plastic plates. Is there something about plastic that will cause screw threads to engage well when hammered?
There are also brass inserts that have a knurled outer surface instead of threads, designed to hammer in. The screw, when inserted expands it slightly and it holds fairly well. I think the threaded insert is probably stronger, and screw it in with a screwdriver and the slot milled into the top.