This is also the reason especially in the Japanese kitchen knives or in knives in general that have only one bevelled side that often many makers perform the hardening without performing the bevelling but doing it later taking great care to cool the blade often or even creating real water cooling systems and using water-resistant abrasive belts .
This method of hardening before bevelling clearly is best suited on blades with thicknesses that do not exceed 3 mm unless you want to consume the abrasive tapes that have a cost.
The key thing is to leave 1 – 1.2 mm of coast line on the wire of the blade before the temper.
La bisellatura prima della tempra
Check with the caliber or with time even to the eye is fine.
If the wire is too thin what happens during the temperise is that the wire melts before the rest of the blade is in tempering temperature.
Do not go with the finish of the blade over the 400 grain as tape and very importantly the plate of the blade must be a plan, so already rectified.
Now that you’re in this condition of wire and finishing it tempts it or bring it to harden.
Ps. Before hardening bring the finish of the blade to 800 grain or more is not needed.
When you leave with the hardened knife never start from the same grain with which I previously “finished” the knife for the temper.
If I’m done with the 400 you usually start from the 220 and then go up to complete the bisellation before creating the wire (micro bevel).
Now let us pay attention to another aspect.
When you work on thin, hardened thicknesses that can heat up to the point of compromising the temper, you need to have some precautions such as:
Put a new (or almost) smoothtape tape without making much friction.
Bathe the blade well before each step at least if you see steam stopped.
Don’t put on your gloves so you feel the heat right away and consider that under 100 degrees you don’t soften anything and I don’t think you’re holding such a hot bar.
Another thing I advise you to do is not to finish the beveling radius or get to where you want the ricasso to end but to leave 3-5 millimeters to give you the opportunity to recover some error to get the symmetry and shape of the beam.
Consider that working with the sander with a hardened blade allows you to have greater precision because the material is harder and consequently the tape by removing less material allows you to have more control to get to the desired detail.