a. A clean tray, free from CR+6 contamination. Maybe wash the tray first. Perform the heat treatment as per making the spring & with the spring. JWST to submit the tray for CR+6 test by Nikon again. This is to prove that the CR+6 present in the tray is coming from the spring. Mark out the area where the springs will sit within during heat treatment as Nikon will cut that portion out for testing. Put at least enough springs to cover an area of 5 cm by 5 cm.