Abstract: A setting tool and liner hanger where the liner hanger has a threaded release section and elongated slip slots for receiving slips. The slips have inclined upper surfaces and inclined tongue and groove interconnections along the sides of the slots defining expander surfaces. The setting tool has a unitary actuating mechanism which can be hydraulically actuated or can be mechanically actuated. Dog members are on the actuating mechanism are releasably connected to internal grooves in the slip members. For hydraulic actuation, hydraulic pressure moves the connected dog members for setting the slips in a well casing. The mechanical actuator operates in response to relative rotation between the setting tool mandrel and liner hanger for releasing a spring force on dog members to move the slips to a setting condition. The tool is raised to a location to set the slips and to release the setting tool from the liner hanger.