DIY Keyhole Hanger Made from a Washer

How to install a keyhole hanger Keyhole hangers: https Keyhole Slot Hanging

What is the proper way to install these keyhole picture hangers? If they are surface mounted, doesn't there have to be a hole or slot for

keyhole slot Keyhole Hanger Installation Soat Mon•36K views · 2:09 Go to Keyhole Slot Hanging

keyhole slot bit Fixing Materials Cabinet hanger, For mounting in drilled hole, keyhole slot