Oil Filter Outside Magnets???

ZoomZ

You'd never know if they work unless you cut filter open.

Also, they can be more harmful than good. If filter ever goes to bypass, even if oil is cold, there is a danger that those particles will get "washed" away from magnet and drawn into system via bypass port.

I'd rather have the metal stuck to pleats. Yes, they can get washed away too, but probably better chance they won't due friction and surface retention.

It would have to be a very strong, quality magnet as you suggest. It wont help you with Aluminum bits.

zz