Each of your knives is an inspiration! Always excellent design and craftsmanship. I'm just an a beginner at making slip joints (only 3 so far). Each was a learning experience -poor design, soldered bolsters falling off, etc. But, the most frustrating experience was when the spring on the best of the three snapped. It is CPM-154. I don't know if the heat treatment was poor or the temper wrong. What HRC do you like for tempering your CPM-154 springs?