Vent: My leaf spring punch cracked after a water quench

I forged a center punch from an old car leaf spring last week. It split straight down the middle when I cooled it too fast. What's the safest quench for spring steel to stop this from happening?

3 comments

3 Comments

the_shane1mo ago

Man, that's the worst sound when it cracks. Been there with spring steel. You gotta slack quench it in warm oil, not water. Heat your canola oil to like 130 degrees first so it's not a shock. Dunk it fast, swirl it for a few seconds, then pull it out and let the leftover heat in the metal finish the job. Water is just way too violent for that stuff.

umaf201mo ago

Brine quenches crack spring steel even faster than water.

singh.jessica1mo ago

My buddy tried quenching a leaf spring in water last year. That loud ping sound scared the heck out of him. Found a crack running right across the middle, totally ruined. He switched to warm peanut oil after that and hasn't had a single piece crack since. The slower cool down just makes all the difference.