DIY case hardening....

[70GTvert]

Davee, here is another tip for reducing that torque from the spring. When you polish your spring ends, how do you do it? Make sure that the end is nice and flat, no edges your finger catches on, and smooth? Good start. Take it a step further, round that flat part of the spring where it was cut down to a nice thin smooth cross section, putting minimal surface area against your bushing. The smaller and slicker a contact surface, the easier for that spring to rotate without taking everything it touches with it.

[SDale]

I harden & anneal my punches & chisels at work all the time. All you need is used motor oil, a good HOT torch set-up and a magnet. A temple stick or some means of measuring temp. is also a good thing to have, but not necessarily needed.

Just heat the steel until it no longer sticks to a magnet, Give it a few taps with a hammer, heat again till no longer magnetic then quench in oil.

Brush off all the ash & slag, heat to a VERY dull red & keep it there for a minute or 2 then let it air cool to room temp. Works like a charm!

Different colors during the second heating will result in different hardnesses after cooling. A Silver gray is the first stage, usually the hardest and most brittle, followed by straw color, then blue, then red.


When I used to make knives, I tried my hand at heat treating & forging with a coal & charcoal pit. Sometimes it worked, sometimes it didn't! Depends on the steel. Gotta have good stuff!