Part 4: Improvised heat treating techniques for knives & tools.

A very highly respected and well known steel among knife and tool makers and available from a large number


of suppliers. 0-1 grade high carbon tool steel can be easily heat treated using many of the same techniques that we covered in the previous post. In this part we will cover from start to finish the application of an improvised heat treat; using 0-1 tool steel.


Unlike the 5160 spring steel that we talked about in part 3  0-1 grade tool steel typically comes already in the annealed state; which allows the craftsman or craftswoman to immediately begin shaping the steel into the desired design. The improvised heat treating process however will remain nearly the same for this grade.


Step One: Grind the steel to the desired shape/design. If making a knife grind/file the edge bevels and drill all handle pin holes before proceeding.


Step Two: Prepare the fire pit and fuel as described in part 2 and allow the wood to burn down until a nice red hot bed of coal is all that's left.


Note: Ideally the bed of hot coal should be at least 4-6 inches deep (the deeper the better)


Step Three: Carefully place the steel on top of the coals and rake a layer over it. This will cool the coals down a little as mentioned above. Allow the steel to stay put for a while and warm up then move it to a new location in the pit and rake a new layer of coal over it. Once the steel becomes the same reddish color as the coals it should be in the 1500 degree range. Once at the temp/color allow it to soak for approx 10 minutes and quench.

Note: The cooler coals in the center where the steel is located 

Tip: Place the steel in the coals just before the fire burns out to get the most out of the bed of coal

Tip: If the coals and the steel look a little too cool fan the top of the coals to bring the temperature and color into the desired range (see temp color chart).

Step Four: Remove the steel from the coal and quench immediately by submerging completely in oil. Once the steel enters the oil it will begin to boil (and in most cases burst into flames and smoke profusely). Submerge the steel in the oil until the oil stops boiling then lift the steel out of the oil and submerge again repeating 3 to 4 times (submerging for 20-30 seconds each time) then place the steel on the metal rack described in part 2 for cooling. Once at room temperature it should be in the 60-63 Rockwell hardness range.
 

Note: see part 2 for recommended oil to steel ratio.

If applying additional tempering quench the steel down to approx 125F then begin the tempering cycle immediately by heating the steel to 375F and soaking for 1 or 2 hours.

Keep in mind that these techniques
are for applying an improvised heat treat.
Rockwell hardness is approximate