Thick edges??

[knarfeng]

It's interesting you notice this. Axe's are often used as the example of a thick edge. I think this must come from most people being familiar with a splitting axe, and having never seen or used a dedicated felling or bucking axe. A dedicated felling axe in the hands of a skilled user can be thin enough to make my Delica blade a good comparison.

Also a bit of caution is necessary to make sure everyone is talking about the same thing. The OP seems to be talking about the angle of the edge bevels, while some others appear to mean the actual thickness of metal just behind the edge bevel. These 2 things are independent of each other, though both have a profound effect on how a knife/axe performs. I've put 10-12 degree bevels on edges 0.055" thick behind the edge, and 30 degree bevels on knives 0.005" thick behind the edge.

I took the original question to be the thickness of the blade just above the bevel, but, now that I re-read it, I think you are correct and he was talking about edge angles. You are right, different issues.

For me, edge angle is mostly dependent on how hard the blade is. The angle I grew up with was 22 1/2°. (mind you I'm talking early 70's and earlier.) Most knife companies went with that angle because the blades were mostly only hardened to 54-55 HRC. So the steel was not hard enough to support a thin edge. You needed more steel behind the edge to support it so that it would not bend. With the advent of newer alloys taken to a higher hardness, thinner edges become supportable.

So, I got up on my soapbox to say that I have some knives that are ~ 54-56 HRC and I tend to keep those at a 20° edge angle. (My 30-year old kitchen knives fall into that category.) I have other knives with blades hardened to the high 50's and even low 60's. Those I keep at 15° or thinner edge angle.

 

[Ankerson]

It's interesting you notice this. Axe's are often used as the example of a thick edge. I think this must come from most people being familiar with a splitting axe, and having never seen or used a dedicated felling or bucking axe. A dedicated felling axe in the hands of a skilled user can be thin enough to make my Delica blade a good comparison.

Also a bit of caution is necessary to make sure everyone is talking about the same thing. The OP seems to be talking about the angle of the edge bevels, while some others appear to mean the actual thickness of metal just behind the edge bevel. These 2 things are independent of each other, though both have a profound effect on how a knife/axe performs. I've put 10-12 degree bevels on edges 0.055" thick behind the edge, and 30 degree bevels on knives 0.005" thick behind the edge.

Yeah the thickness behind the edge will make a huge difference, really huge. As you hinted at the thinner the steel is behind the edge the larger the angle would need to be, something that is .005" behind the edge I wouldn't go below 30 degrees inclusive, 40 degrees inclusive would be even better on a work knife. A blade that thin will cut like a laser with a 40 degree edge even if it's dull it will still cut like crazy.

I think you are right though, he might have been talking about edge angles and that will depend a lot on the Steel, what hardness it is, how thick it is behind the edge and the use of the knife.

 

[me2]

I meant 30 degrees per side, 60 inclusive, and 12 per side, 24 inclusive.

 

[me2]

I suppose that's true. But I don't believe it's worth the trade off. To loose the ability to cut most anything easily, and gain the limited ability to cut some hard things. And I believe if it turns out that you need to do a lot of cutting things that you probably shouldn't cut with a knife, then you should carry a proper tool for that job.
But, different strokes for different folks.

I'm with you, but there are people who would rather have the latter for that once a month time they need it. I usually take a middle ground approach.

 

[Ankerson]

I meant 30 degrees per side, 60 inclusive, and 12 per side, 24 inclusive.

Yeah with .005 you can get away with 60 inclusive.

 

[Calmbro]

It's interesting you notice this. Axe's are often used as the example of a thick edge. I think this must come from most people being familiar with a splitting axe, and having never seen or used a dedicated felling or bucking axe. A dedicated felling axe in the hands of a skilled user can be thin enough to make my Delica blade a good comparison.

Also a bit of caution is necessary to make sure everyone is talking about the same thing. The OP seems to be talking about the angle of the edge bevels, while some others appear to mean the actual thickness of metal just behind the edge bevel. These 2 things are independent of each other, though both have a profound effect on how a knife/axe performs. I've put 10-12 degree bevels on edges 0.055" thick behind the edge, and 30 degree bevels on knives 0.005" thick behind the edge.

Sorry I wasn't at all clear about this and when you mention it - My main question is actually about knives with a sabre grind that is thick (I believe it's called, correct me if I'm wrong) for example some Tops knives are not very good at chopping and carving because of this - to what purpose? And if anyone can educate me on techniques to use this kind of edge please do.

Other knives like Cold Steel Trailmaster or a Black Jack Panga has a flat grind and even if the edge bevel is steep they still cut great I think - that's not the kind of edge I'm thinking about.

Thanks to all for the interest in this question - all answers has been educational for me

 

[me2]

I have generally avoided Tops knives because of that issue with geometry. Their number one goal appears to be strength, not cutting ability, which is fine, just not what I look for in a knife, usually.