What hardness should i aim for in a 8" chopper

J

Joshua James

Joined
Apr 16, 2014
Messages
11
Hey im a complete newbie and was just wondering what rockwell hardness i should aim for in my first knife
Im thinking of making it out of 5160 with a full tang and just a very basic drop point with a false edge partway up the spine
 
56-58 are common values for that kind of knife. I'd temper it at 450F.
 
Last edited:
Thanks for the help skeptikos
Also what is the easiest way to get a softer spine without a torch i may be able to use clay but only maybe
 
Joshua James said:
Thanks for the help skeptikos
Also what is the easiest way to get a softer spine without a torch i may be able to use clay but only maybe
Click to expand...

I doubt clay will help you. 5160 is a deep hardening steel. You can quench it relatively slowly and will still achieve full hardness. If you read an isothermal diagram you'll see the "nose" is at about 5 secs, while for 1095 or W2 the nose is at 1 sec. The only way I can think of to get a soft spine without a torch is quenching the edge only. The spine will be made out (mostly) of pearlite, softer and tougher than the edge.

One word of caution: edge quenching tends to produce some flames and smoke.
 
It also shortens the life of the oil !! Your oil container must be metal .Have a snug fitting cover - the fastest and safest way to put out the fire if one should start !
 
Joshua James said:
Thanks for the help skeptikos
Also what is the easiest way to get a softer spine without a torch i may be able to use clay but only maybe
Click to expand...

Heat a chunk of steel to a red heat and rub it along the spine until the colors start to run.
 
navasky said:
Heat a chunk of steel to a red heat and rub it along the spine until the colors start to run.
Click to expand...

Nice tip. Another possibility is to use a kitchen stove. A gas burner is not very precise for a small blade but for a larger chopper may do.
 
You must log in or register to reply here.
Back
Top