Do not heat the springs. Music wire as received is already heat treated properly. Forming a coil or other shapes does cause slight additional work hardening, but not enough to cause problems. Small commercial wire springs are formed directly from heat treated wire and are ready to use right off the forming machine. Larger springs are formed from annealed wire( in some cases, red hot wire) because the forming forces and machine wear are much less. They are heat treated after forming. One more point, a kitchen oven is a lousy heat treating device because the temp controller is usually very crude.
OB
