Our thread tension devices employ the sewing industry standard design of tensioning thread. Position the thread between the polished chrome tension plates. The spring loaded knurled nut makes it easy to find the desired thread tension for your custom rod. The tension devices 0.187″ diameter mounting spud fits tight inside a hole drilled with 11/64″ or #17 drill bit. Replace, add to or build your own thread control board with Flex Coat Tension Devices.