[kaisen]

I'm betting your 2000 F150 has a RFID chip embedded in the key head. Want to see a picture?

I hope you made a NEW key based on the VIN, and not a copy of the already worn key. Otherwise you keep damaging the tumblers. My guess is they are already shot. Will cost a little over $100 to have a locksmith re-do the tumblers, make a new key shell, and transfer your old RFID to the new key. It'll be about $50 more to have the RFID system reprogrammed by the dealer if you want more than that one key.