Record root diameter
Vol.19 #3, Nov. 1992
Next time you remove a screw for cleaning, consider recording the root diameter dimensions as measured by verniers, albeit a rough estimate, it could prove useful for troubleshooting a host of processing problems.
Be sure the root is cleaned of polymer and/or degraded material.
See also
Screw installation 1
Screw removal 1
Screw removal 2
Screw removal 3
Screw removal 4