Oil hardening vs water hardening for tool steel - which is actually better?

I was reading that old copy of "Practical Blacksmithing" by Richardson I picked up at a flea market in Topeka last summer, and it claims water hardening gives you a tougher edge on chisels, but I've been doing oil hardening for years and it's fine. The book says water quenching creates more stress fractures, but my grandpa swore by it for decades. I'm curious what everyone else here uses for things like drifts or hot cuts, and if you've actually seen a difference in durability.

3 comments

3 Comments

emery1929d ago

Water quenching does give a tougher edge on certain steels but the risk of cracking is real, especially if you're working with thinner stuff like drifts. Oil is way more forgiving, and unless you're using a specific high carbon steel that needs that fast quench, you're not losing much toughness with oil.

walker.cole29d ago

Different steels though. Some of that simpler high carbon stuff really does benefit from the fast quench. I've cracked a few thin pieces in water so I know the risk, but a slow oil quench on something like 1095 can leave it too soft.

robin_roberts841d ago

Grandpa mighta been onto something if he was using O-1 or similar high carbon. Water quench on that can give you a super hard layer right at the edge, almost like a natural carbide layer, which chips less on stuff like drifts that take a beating. Oil soak is more consistent for thick cross sections though, like a hot cut hardy, where the inner core needs to stay tough to avoid snapping under heavy blows. I've got a set of W-2 chisels I quenched in brine and they hold an edge way longer than the 5160 ones my buddy brought over, even though they're a pain to sharpen without a good stone. So it really depends on the steel chemistry and what you're making, not just which method is newer.