A method for manufacturing a nonlinear superelastic file comprising the steps providing a superelastic file having a shaft and a file axis; providing a fixture including a groove being defined by one or more displacement members, the file groove configured receiving the shaft; inserting at least a portion of the shaft into the fixture along the file groove the portion of the shaft including a first portion of the shaft; contacting the first portion of the shaft with a first displacement member of the one or more displacement members such that first portion of the shaft is displaced from the file axis thereby forming a first offset portion of shaft; heating the portion of the shaft while inserted in the fixture to a temperature of at least about 300°C for a time period of at least about 1 minute to shape-set the portion of the sh thereby forming a shape-set nonlinear file.