In the Hubbard Catalog No. 24, (circa 1924) reference is made to the twist driven thread. This thread type is shown being applied to a pole step for a wooden pole. Also shown is a pole step with a Fetter drive thread to be used with wooden poles. The Fetter drive thread is the type found on metal pins using wooden threaded cobs. Is it possible that the twist driven thread could have also been applied to metal pins with applied wooden cobs? Similiar information was found in the Joslyn Catalog No. 10, (circa 1926)