Ferro rod affecting heat treatment?

J

jgn

Joined
Jun 17, 2013
Messages
78
Just a simple question.
Will the heat from striking a ferro rod, ruin the heat treatment of a knife blade?

just wondering.

Jonas
 
No. Most blades are tempered at around 400ºF or higher... To ruin the heat-treatment you would have to get the entire blade up to above 400ºF.
 
No, it won't. Also, don't use the edge of the knife. Square a spot on the spine off, if you already don't have a squared spine.
 
That blade is subjected to "sparks" more than any real heat, and to a VERY small area of the blade. Any heat there is quickly drawn away by the rest of the blade...thermal conductivity...
 
Nope, not gonna do one ounce of harm, aside from some dulling if you are striking with the cutting edge.
 
aarongough said:
No. Most blades are tempered at around 400ºF or higher... To ruin the heat-treatment you would have to get the entire blade up to above 400ºF.
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I thought heat treating was generally north of 1500 degrees depending on the steel?
 
What about knives with low HRC heat treating? Like Victorinox and Case's Tru-Sharp...
I've always wondered this too.
 
bladeboss said:
What about knives with low HRC heat treating? Like Victorinox and Case's Tru-Sharp...
I've always wondered this too.
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This if for the quoted post and the one above it. The heat treating process is a multiple stage process. Steel is heated to a proper temperature, specific to each steel, Sometimes 2000f or more but basically never below 1450. The steel is then rapidly cooled hardening the steel. If you left the steel like this it would be super hard, but about at delicate as glass. The steel is then tempered back by heating at a lower temperature to soften the steel up some and give it some toughness back. The higher the tempering temperature, the softer the final hardness will be. So to answer the questions, softer blades can typically withstand a higher temp before sustaining further unwanted softening. Keep in mind that virtually no steel is tempered at temps below 350, so unless your ferro rod is heating a large portion of the blade to 350 or greater, (which it won't) there is no danger.

This is an oversimplification but it's about the best way I could think of to explain it without getting into a full on discussion on metallurgy. Remember, most people call the entire heat treating process tempering, it's not. That just one of the steps in the overall process of achieving final hardness
 
FroOchie said:
I thought heat treating was generally north of 1500 degrees depending on the steel?
Click to expand...

heat treating is done at that temp, but at the end of the process the steel is very hard and brittle. To let the steel be more malleable and "tough" and keep it from shattering, it is tempered at 400 or so degrees.
 
heat treating is done at that temp, but at the end of the process the steel is very hard and brittle. To let the steel be more malleable and "tough" and keep it from shattering, it is tempered at 400 or so degrees.
Click to expand...

Some have tempering temps in the 1000 deg. F. range.
 
Sonnydaze said:
That blade is subjected to "sparks" more than any real heat, and to a VERY small area of the blade. Any heat there is quickly drawn away by the rest of the blade...thermal conductivity...
Click to expand...

This. The rest of the blade acts like a heatsink drawing heat away from the heated area. It's unlikely you could get a small spot that hot, that fast. Also it would be friction that accounts for most of the heating of the blade, it any. Not the sparks. There is no thermal conductivity between the sparks and the blade.
 
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