For coils up to 750kV, 18" diameter x 4.5" height spun aluminum with ¼" center hole.
These are spun aluminum of grade 1100-O (99% pure aluminum), with a welded seam that has been smoothed and polished and cannot be seen. Aluminum wall thickness is approximately 1/16" (so the flat central area is about 1/8" thick, for example). Excellent for Tesla coils requiring a capacitive terminal and high voltage DC generators.
Our laboratory has the tooling and now offers many sizes of toroidal terminals: have a look at our PDF sheet to see other available sizes from 3 to 98 inches!
Quantity discounts available -- contact us for more information.