Looking for history of 5160 spring steel

[Chris Evans]

Originally Posted by Ian

Chris, would not some of these mirco-cracks be corrected during the forging process?

Maybe, but chances are against it. The inside surfaces of the crack become oxidized and are unlikely to weld shut, unless a flux is introduced.

The practice of recycling used leaf springs is not best practice because for starters one does not know the steel's composition and thus the heat treatment cannot be optimized. And then there's the matter of the said fatigue cracks.

In summary, it is one of those things that is widely done in the poorer regions of the world with the assumotion that near enough is good enough and things are OK until they are not.

This subject has been discussed over and over on blade smith forums and the experts always prefer new steel of a known composition. After all, plain and low alloy carbon steels are quite cheap.

Cheers
Chris