My last few O1 blades have developed a bit of a curve after heat treat. The first time this happened I was able to grind them straight. The one I just did I clamped straight in the temper stage, but there was still a bit of curve so I tried to bend it back and the tang snapped off!
I have a light weight jig that holds the blade vertical in the oven and heat soak at 1475º f. for 5 minutes, quench in fast quench oil followed by 30 minutes at -100º f., then 2 2 hour tempers at 340º. This routine has been working really well until now.
The steel is from Starrett through McMaster-Carr.
Does anyone have any suggestions?