These are Nylon tip inserts for m3 or m4 set screws are used to lock agaisnt shafts where insulating value or conforming properties of nylon are desired Nuts from Hot Racing.
FEATURES:
Nylon construction inserts.
INCLUDES:
(4) Nylon Locking inserts
SPECIFICATIONS:
diameter: 2.5mm
height: 1mm
COMMENTS:
This set screws Nylon Locking inserts lock tight and won't mar the mating surface or the mating part. For instance, they can be used to lock against fine threads and to remove end play from rotating shafts. will not loosen due to vibrations.