This document has been declared "Stabilized" and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability or technical requirements. New technology may exist.An analysis was made of the effects of various surface conditions on the het up time of steel bars which are heated in atmosphere furnaces to the temperature range used for steel hardening or normalizing. The purpose was to examine whether a standard heating time for a given section thickness is acceptable.