Minimum Edge Thickness

[kdkerr2]

I'm in the process of building a new tanto from scratch. My blank is 440C. I need to know what is the minimum flat edge I need to leave on the edge so that too much carbon isn't burned out while soaking in the furnace, leaving it soft. Before I retired most toolmakers had a rule on knife edges of no less then .020" but we were working with mostly AISI alloys of D2 and A2 tool steels.
KK

[SBuzek]

I usually take mine down to .020 and had good results.Thinner and if your grindss are uneven will give you some edge warping.

[son_of_bluegras]

I've been able to make 0.020 to work though sometimes that thin gave me fits. Usually I shoot for 0.030 to 0.040. Of course I'm mostly working by hand and the heat treat is in a coal forge.

ron

[Echo 29]

I've heard the thickness of a dime is a good way to eyeball the thickness pre-HT.

[squigly1965]

Yea I was told thickness of a dime as well
which is about .06

you can go thinner as many people do. Even with out consequence, if you are Lucky. But it is what I would suggest.
And to aid in the metal removal I dont have a Belt grinder. I was told to use a single cut file. Which worked relatively quick. I was working on O1 steel.