[Allanw]

Originally Posted by tbirdtbird

So oil filters are for road dirt, hey?
What about metal filings from internal wear of rings, bearings, gears, etc.
Those of you who are filter naysayers need only remove the side cover and wipe your finger along the bottom of the valve chamber. Then report back if you discovered any metal filings. Or maybe lots of 'em. No chance they could work their way into the oil hole for a main or anything. Then think about the bottom of the pan and the bottom of the dipper trays...couldn't possibly be any metal filings in their, either.....
Try it, and report back what you find.

Ermmm... metal filings big enough to get caught in an oil filter are NOT normal wear and tear.

An average oil filter only filter down to about 20-25 microns.