My uncle said to always quench a leaf spring in used motor oil, but my last blade cracked straight through.
I tried his method on a truck spring knife blank, heating it to what I thought was a good orange, then dipping it in a bucket of old 10W-40 from my shop, and now I'm out a day's work and a good piece of steel, so what's a better quenching medium for that kind of steel?
Took my dad's old advice about saving money and just changed the numbers for today's prices. Started putting half of what he said into a high yield account instead of a regular one, made a real difference after a year.