What are the little screw fillers called that hold the belt tensioner bolt??? on 1999 Chevrolet Malibu

When i took the bolt out to replace the belt tensioner i got screw filler shavings or what looks like a boltscrew holder inside.. What are the called and how do i ask for them???

Asked by for the 1999 Chevrolet Malibu
3 answers
What ever you are doing, just replace the bolt and tighten to install the tensioner.
poss a locking solution on all factory installed bolts