Our laboratory has the tooling and now offers many sizes of toroidal terminals from 3" to 98". Have a look at our PDF sheet to see other available sizes from 3 to 98 inches!

These are spun aluminum of grade 1100-O (99% pure aluminum), with a welded seam on sizes above 12" that is smooth 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 up to 1.5 million volts. (Note that high voltage DC generators require a highly-polished surface to prevent leakage losses, which is contrary to Tesla operation where you want air leakage to make the sparks. High voltage DC generators should also use seamless toroids as these are easier to finish to a smooth mirror-like surface.)

Toroidal terminals used for Tesla coils are for producing a capacitive load that lowers the impedance of the output, consequently giving a hotter and brighter spark. These pieces do not require smooth or shiny surface as do toroids used for high-voltage DC power supplies where smoothness is mandatory to prevent high-voltage Corona leakage.

Quantity discounts available. View free PDF sheet for other available sizes.