anealing and tempering metal

[CedarSlayer]

Christophe, how could I deny you? You have Carte Blanche.

Looking it over, I should add a few notes. First, wear safety glasses. Second, on the oil vs water quench, The most reliable test is to do both if the difference is not dramatic, the real test is to see how well the best spring tempered section will handle extreme bending and how well the blade tempered section will sharpen and hold an edge. Cutting pine end grain is a classic test for edge retention.

When testing scrap I also check to see if spring tempered steel can be made into a scraper with a burr. If it can it is work hardening. Work hardening can be an indicator that it's life as a spring may be short. The best sythe blades I have used are work hardening.

Bob