Rockwell for Different Type Knives

[AKHammonds]

Hello-

I am sure this question has been asked and answered dozens of times but I did do a search and could not find it. I am working with 5160 and 1084. Just got my Rockwell tester and would like some kind of chart as to what Rockwell to shoot for the different type blades. Say like Rockwell 48-53 for chopping blade and 56-60 for a hunter or whatever it is? Has anyone seen such a chat? And if so where can I get a copy?

Thanks
Allen

 

[TheOTBalisong]

48-53 is much too low, for choppers I would put it at 58/59 and (depending on steel) for hunters, 61/62.

 

[me2]

It's a huge range, and depends on steel type, heat treatment, and geometry. I have a large (12" blade) chopper of S7 sitting ready for handles at 58 HRc. I have a kitchen knife in A2 at 61 HRc. I have another kitchen knife waiting for a rat tail tang handle that's at 65 HRc. I have long term plans for a large wood/brush blade in the 53-55 HRc range and a large kitchen knife at 65. There are makers putting out blades for bone chopping above HRc 60. The high hardness blades are M2 or similar. The bone chopper is S1 shock steel, and the large brush blade will use 4340, if I can find some. My current hard use blade is a Cold Steel Barong machet. Heaven knows how hard it is, but I'll SWAG it at 50 plus or minus 5 points. No problems with it durability wise, and it's held an edge that would shave my arm through a day of wood work, trimming branches, weeds, etc.

 

[james terrio]

I don't like sharpening very much so I try to keep my blades on the harder side. As the others say, final hardness depends on intended use, edge geometry and the steel you choose.

I'm made a couple choppers out of 1084 tempered at 58Rc and they hold up very well to rough, dirty work - no major chipping, just normal wear that can be sharpened out. If you're doing the HT yourself you could shoot for a tempering range that will get you to 60Rc and test it on whatever you would normally cut with it, with the edge sharpened the way you like. If it's a bit too chippy, you can re-temper at a slightly higher temperature to bring the hardness down a point or two.

You can always temper again to make it a bit softer, if you start out too hard. If you temper it too soft to begin with, you'll need to start all over and re-harden it.