Fuzz
Fuzz turns up in 2 fields: gears, nonwovens. Here is what it means to the people in each one.
Fuzz in gears
Shop word for the fine metallic paste that collects on a magnetic drain plug from normal gear wear.
The fine, furry layer of ferrous wear particles that builds up on magnetic drain plugs and chip detectors. A light coat of fuzz is normal, especially after break-in, while flakes, slivers or chunks point to pitting, spalling or a breaking tooth or bearing. Mechanics read the plug at every oil change as a cheap condition check.
"Just fuzz on the plug, no chunks, so the gears are wearing normally, wipe it and button it up."
Fuzz in nonwovens
Loose fiber ends on the surface of a nonwoven that lift into pills or lint when rubbed.
Fuzz is measured by rubbing the surface with an abrasive or a fabric under set conditions and weighing or rating the loose fibers that come up. Light bonding, low bond area or weak bond points leave filaments free to pull out. Topsheets and outer covers that fuzz look worn and shed onto the wearer, so fuzz is always traded against softness.
"Softness score is great, but the fuzz rating failed, so add a touch of bond area back."