: Normally a time gap of 8 hrs is accepted for alloy steels and about
: a day for neutral hardened steels. For case hardening including
: carbo nitriding a delay of 4 hrs max is allowed

For any steel carburising , carbonitriding , alloy steels : temper delay time must be within two hours form the end of quench time as per standard the AMS 2759/1 , 2 , 7

For plain carbon steels this delay time can be adjusted depending upon the geometry of the part.