Basically oversize washers, these 2mm thick, fabricated steel discs are used every day in the duckfat workshop. When used with threaded tube, a washer & locknut, almost anything can be turned into a light shade.
Sold as a pair or in packs of 10, these donut discs make the impossible possible.
Disc 1. : 40mm diameter, 26mm inner hole diameter
Disc 2. : 32mm diameter, 11mm inner hole diameter
Disc 3. : 60mm diameter, 11mm inner hole diameter