Spring temper problem

[John L]

I make folders. I usually use D2 and know the temps I must hit for correct hardness and spring temper. I decided to use some O-1 thinking this would be a no brainer. Problems..problems..problems. I have researched the spring temper for O-1 and have found 6 defferent temps for R50-51. Heat Treaters Guide shows 800F. Tool Steel Simplified shows 700F. A lot of the knifemakers websites normally use colors, not temps. I must be colorblind. Well..I used 800F for spring temper and springs would not tretain shape under tension. I used 725 and popped the next spring. What do those who use O-1springs on folders use? Many thanks.

 

[heatride]

John my chart says 900 F will give you 44/47 RC on O-1 and thats about were I would want mine .

 

[Don Hanson III]

Back when I made lots of slip joints, I made hundreds of springs from 01 and never had one break. I would temper the spring with the blade @ 450f, for one hour, twice. Then heat the spring with a torch to a even blue color.

Also be sure not to over heat the spring when heating to quench. A good temper will not help an over heated spring.