Magnetic Metal Chip and Shavings Catcher

The DH has been disassembling some old PCs to recycle the parts. While taking apart a hard drive he came up with a use for the powerful magnet inside. He needed to drill through a piece of sheet metal on our new heater ducting and thought to use the magnet to collect up the bits of metal at the source rather than clean them up off the floor. The interesting thing about these magnets is that only one side is magnetic. The other side is somehow shielded thus requiring that it be attached to the duct. He simply taped it to the duct (magnetic side out) with masking tape and drilled his holes. The magnet collected the shavings neatly, as seen in the second and third photos.