Tempering 5160 for Large Batoning Chopper

I feel like I've read 100s of forum posts on tempering 5160, and still have doubts about what temperature I should be tempering my large chopper knives at that will be used for batoning wood.

I even read Ed Caffery's thoughts on 5160, but when it comes to tempering toward the end, he gets kind of vague. He seems to say 350 to 365, but I'm not even sure what size/type of knife that was for. Therefore, I've been doing 2 tempers at 350. Is this ok for a 5160 chopper?

So, my goal is to get a 9" blade chopper whose main purpose is to handle the abuse of batoning without snapping off the end. Edge retention is not quite as important as overall toughness.

I wish I had the luxury of destructive testing blades, but as of yet I am a small time hobbyist who uses an angle grinder, files, and sheet sandpaper to create maybe one knife a year just for the pleasure of it. So by the time I finish one it would make me cry to simply destroy the thing in a vice to see what works and what doesn't. Therefore, I am more than happy to simply get a bunch of opinions and that will give me a good starting point. Over time I'm sure I'll figure out the temper temperature I prefer, but until that time I look forward to your ideas.

David B.

Hi David!

I have to smile when I read

(I even read Ed Caffery's thoughts on 5160, but when it comes to tempering toward the end, he gets kind of vague. He seems to say 350 to 365, but I'm not even sure what size/type of knife that was for. Therefore, I've been doing 2 tempers at 350. Is this ok for a 5160 chopper?)

Click to expand...

Although the way I word things may appear as vauge, its more so from the aspect of knowing that there are no absolutes when it comes to things such as tempering.....simply because the "correct" tempering temp used on any knife depends on a number of variable factors...... of course steel type is there, but also grind and edge geometry, thermal treatments, and even sharpening angles can come into play. There was a time, when I would give advice for things such as tempering temps based solely on my own experiences and work....but as I matured as a knifemaker, I realized that many factors come into play, and that for me to say exact numbers would just be arrogant assumption on my part.....therefore whenever I offer my advice, I try to remember that there could be variables, hence the reason I don't often give exact numbers.

OK, that being said, I tend to do a lot of differential heat treating with 5160, it is one steel that I have found benefits from that treatment, I also tend to grind fine geometries on smaller blades, and slight more robust edge gemonetries on larger blades. So, my formula for 5160 often goes like this:

1. Forge to shape
2. Thermal cycle 3x.
3. Anneal, rough grind
4. Thermal cycle
5. Edge quench x3 allowing the blade to cool to room temp IN THE OIL between quenches
6. Temper at 350F x3 allowing the blade to cool to room temp between each tempering cycle.
7. Finish Grind
8. Fit guard/handle
9. Final hand finishing
10. Assembly and finishing
11. Testing

I can fully understand the reluctance to do destructuve testing, Early in my career I shared that same feeling. In those days, like you, I felt as if I had put so much time and effort into a knife.....why would I want to destroy it?! However, when I finally broke down and starting testing, and moved into the realm of destructive testing, my knowledge expanded expodentially.

It gave me the insight and the understanding to sort through information and more accurately determine fact from opinion. Not to say all the information on the net is bad, but I have come to understand that a considerable amount of information concerning knifemaking on the net is often hearsay, second or third hand, and even what I call "arm chair expert advice".... information that has been derived from an individual(s) reading information, and although they have never ground a blade, or lifted a hammer, recount it as absolute, because they read it.

I honestly believe that when it comes to knifemaking, there are many different paths to the same destination. The information I try to relay, are the methods and procedures that work best for me.....they are certainly not the only way, but they are my way(s).

I guess the whole point to my sermon is this.... Knifemaking is not a craft that can be quantified by absolutes....there are variances from maker to maker, and method to method. In the end, I feel its necessary to break a few eggs, before you can make the cake.

I can't add much to what Ed said and couldn't agree more.

I have almost zero experience with 5160 but I will add this: You don't have to completely destroy a knife in testing. There are lots of real world ways to test a blade that may result in fixing a few small chips, rolled edges or the like but won't ruin the blade.

Cutting sisal rope, cardboard and maybe chopping on pine knots will tell you a lot about your blade. Especially when you compare them to known results in the same materials with a knife of known, tried and true quality. And none of them should destroy your blade.

David, I have zero experience with that steel, so I can't add to what Mr. Doyle, and Mr. Caffrey have said. But I can tell you that these two guys give good advice, and know what they are talking about.

Man, to get a reply from Ed Caffrey and John Doyle means a lot. I really respect both of your opinions, and am very excited to hear a reply straight from the horse's mouth (not that I'm calling you a horse or anything). One of the reasons I decided to start my knife hobby by making them out of 5160 is because of your well-worded discussions on it's positive attributes.

I realize there are thousands of perameters that go into each knife, but I'm grateful that you were willing to give me a starting point. I also love that you listed your formula for me. That's a great jumping off point too. I will add another temper cycle to what I've been doing but keep it at 350 seeing as so far the few knives I've made seem to have pretty good edge retention and I haven't cracked one while beating it through a stick with a stick (I take these backpacking and it's much lighter than an ax but almost as effective if it can be beat on a bit).

I also looked up what the heck "thermal cycling" is and will add 3 of those before the quench. I've just been stock removing (and recently with pre-annealed stuff from Jantz), getting it to 120 grit finish, and then quenching the whole blade portion, not edge quenching. I now have a couple new techniques I need to try.

Thanks again for the great replies!

David B.

Oh, and MVPeterson, I saw this knife on your facebook page, and the one in the foreground is exceptionallly beautiful in its simple elegance. That's the perfect, medium-sized, fixed-blade shape.

Good advice given all around. The only thing that I'll add is that when testing, I suggest you start your temper on the low side and test the blade before finishing. You can always re-temper at a slightly higher temp. if you have chipping issues.
You can always draw the blade at a higher temp. to make it a little softer but if you need more hardness you have to start the H/T process over by re-hardening. When experimenting remember to only change one thing at a time and keep good records. Soon you will know what temps. you need to make anything from a thin slicer to a heavy chopper and anything in between.