Convex Edges: How Thin Is Too Thin?

[Horn Dog]

The subject has come up before. While many users are quite happy with factory edge bevels, I prefer the ones like the CE Busses came with. So I usually thin the edges on mine. But the hardest thing I chop is wood. I already know from experience that hitting a rock or concrete by accident does a number on my edges. But it's the price I pay for better cutting and chopping performance. Not only Busse Competition Edition knives, but many Bark Rivers and even Condors come with sharp convex edges. My thinking is, if these choppers in 1075 or 420HC hold up pretty well with such edges, then so should my Bushwacker in INFI. And so far, it has.

Here is a Condor Golok machete in 1075 steel. It came with this thin convex edge, and it has a 14" blade just made for chopping.

And here is my Bushwacker, with my thinned out convex edge. With this edge it slashes through tough brush like it was celery stalks. It chops hardwoood, too.

So what type of knife use would make me want to keep a less sharp edge? And how thin is too thin?

 

[d762nato]

Nice, Thoughs are some serious ChopWackers you've got there.

 

[Horn Dog]

Thanks, but I am still wondering about INFI. I know it is higher hardness than the machetes. I admit, this is as thin as I want to go, and thinner than most of my other Busse edges. I have beat the heck out of this Bushwacker on all kinds of wood, and the edge is still shaving sharp. The little stuff you see on the edge is just lint from the sheath. The edge is still pretty much as it was when I did it. My 1095 RTAK with an equally thin edge showed some tiny chips after use, but not the Busse. Of course, the damage was barely visible and is easily corrected. How thin can you go with INFI?

 

[d762nato]

I wish I could answer that one. But Infi must really be some tough stuff to take that kind of pounding, and still be shaving sharp. I guess that's why where all here, Ain't it Great!!!

 

[tomthebaker]

Any thinner than I sharpen is BAD!!

 

[Ankerson]

You will know it's too thin when the edge starts chipping out.

Then once that happens you can reprofile it to a thicker edge.

 

[Volk]

There was a fellow here when I fist joined by the name of Noj something, he would sharpen all his knives, and he settled only when the knives were able to split a hair in two.

 

[230grains]

Many sharpen their knives to that degree, my ASH-1 is currently sharp enough to make fuzz sticks out of hair. It doesn't last, but it stays shaving sharp for quite some time. A little time on a strop with some green compound, followed by some pink.

 

[Horn Dog]

Thanks, guys. I really don't plan to ever go any thinner than I did with the BWM, but I am amazed at the strength of that edge. INFI rules.

 

[HuntBomb]

I also convex all of my fixed blades to a rather thin and shaving sharp edge because I haven't found another edge that compares when chopping wood.
My NMSFNO (Arctic + Black Mags) was immediately ground to a pretty thin edge when new, and it has chipped several times from chopping dense wood that was full of knots, but they don't decrease it's chopping ability.
The dings/chips are worked out after about an hour of sharpening with a course DMT, while watching an episode of Law and Order.
--My RS6 Raven WSK has an even thinner, insanely sharp edge (SKS-5 HC), which dents/rolls everytime I hit a knot, but I can fix it in about a minute with a fine DMT.

-Hunter

 

[richstag]

I agree with Ankerson. You will never know with your particular knife until you go too thin. Then just take it back a little. With all of your usage of machetes you should be used to thin edges. I know my ontarios have paper thin edges that hold up just fine. All IMHO

 

[Horn Dog]

My Bark River Golok was ground quite thin, and I managed to chip the edge a little. So I reground a thicker final edge on it. But most of my experience with really thin edges has been with 1095, 1075, 420HC and 0170-6.

 

[Ankerson]

I agree with Ankerson. You will never know with your particular knife until you go too thin. Then just take it back a little. With all of your usage of machetes you should be used to thin edges. I know my ontarios have paper thin edges that hold up just fine. All IMHO

I tested my BWM with a nice 30 degree edge (15 degrees each side) and it held up great, bit very deep in the wood. :thumbup:

 

[richstag]

Good to know Ankerson, thank you.

 

[Ankerson]

Good to know Ankerson, thank you.

No problem, I didn't want to make a thread about since 30 degrees isn't really that bad.

 

[PeterPHWS]

Vic, could you try cutting into a ball of putty or clay or whatever medium leaves an impression of the edge geometry and measure the angles you have taken some of your knives to?

It would be interesting to know....sometimes with your polishing belt finish on the edge it looks quite "high" and therefore seemingly a pretty acute angle....some look to be 30 degrees inclusive or less...which is a fair bit thinner than I have ever taken chopping knives to....and it would be good info to know where they can still do well at without "rippling" the edge....