[Woodcarver] Knife making question

[Joe Dillett]

What repicy do YOU have to harden (or unharden) steel Joe ??

                                   Woodbutcher Jan
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Hi Jan,

Steel that can be harden must be high in carbon. One can burn carbon out of steel by overheating so care must be taken while grinding.

To harden a piece of steel heat the steel so it is red (cherry color) hot (this is generally done in a forge). Quench it quickly in oil. This will harden it to maybe 72 Rockwell. Test it with a file. If you draw a file across the metal the file should hardly scratch it. It should be about as hard as the file. 72 Rockwell is too brittle for a chisel, it will shatter or chip easily. The hardness needs to drawn back to about 62 Rockwell so it is less brittle. To do this polish the steel to a bright silver color. Heat the metal to a straw color and no hotter (maybe 450 degrees F. Even a toaster oven will do). Quench in water. Now try the file and it should remove some metal but still remain hard enough to hold an edge. That should be about 62 Rockwell.

Joe Dillett
The Carving Shop
645 E. LaSalle St. Suite 3
Somonauk, IL. 60552

(815) 498-9290 phone
(815) 498-9249 fax
http://www.thecarvingshop.net [business web site]
http://www.carvingmagazine.com ['Ask Joe' column]
http://community.webshots.com/user/joe_dillett
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