Would a more acute bevel hurt anything...?

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SuzukiGS750EZ

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Dec 30, 2008
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I found that the 40* bevel that came with my custom was too steep and it wasn't all that good for doing what i do in the woods. I accidentally was sharpening on a diamond stone and did both sides a little more acute than 20 per side. When i throw it on the sharpmaker on the 40* side, i have to lean it slightly towards the stone to get the whole bevel, not flat, maybe 1/4" or so away from it. Don't know what angle it is, but when paired up with the 30* included side of the sharpmaker, it makes for a rediculously sharp blade. It's made of 01, do you see any problem with these angles/steel as far as durability? It stays sharp through some chopping tasks, the point seems to be more usable and it definately cuts like i want it to, but i wanted to know if
A) What i did was all right
B) Will it hold up to harder use
C) Any advantages/disadvantages?
The reason it came out like this was because i was trying to convex, and after destroying the shoulders, but not convexing, i threw it on the diamond stone like i have many times before. But yeah... it came out like this. Oops! The 01 is 5/32" thick. Thanks for any help!
 
you should be just fine.

an acute edge will slice better than an obtuse edge, all other things being equal.

it will also be more prone to deformation/chipping since there is less metal. but worry not, i prefer my knives be at about 30 degrees inclusive as well. in reality, you haven't changed the edge angle drastically, but i suspect you will notice the difference in performance.

i would suggest not going any less than 25-30 degrees.
 
And then the actual cutting edge is at 15*, correct? So my bevel is probably around 17* would you guess?
 
Do you think i would notice any chipping on a 5/32" 01 4" blade? All angles are the same on it. The most id do would be chopping into green trees or chopping branches off of a dry piece of wood to delimb for a walking stick. I don't baton, and if i did it would be just to make kindling wood for a fire, nothing huge. What do you think would deform the blade? So i guess what i did was a good thing on my part then?
 
Oh, and now it splits hair, where as before it didnt. Did the change in the back bevel really make that much of a difference to the initial edge?
 
You better return it back to the original edge angle ASAP before it falls apart!

I don't understand everything you are asking especially the 1/4" part, but really no one can answer any of these questions without using the knife. Which is what you should do and you will find out how the edge holds up. You can't do anything about it now so use it and see how it holds up. If it does seem delicate then just start sharpening at 40 deg again but any quality knife should be able to work well at 30 deg unless you are hitting rocks and metal with the edge.

And there really is no way of knowing what angle you have sharpened it at. If you want to know get a micrometer and use some trig to figure it out. But to my knowledge you can't put a microbevel on a knife that is more acute than the edge bevel. So 17 deg with a 15 deg edge is basically impossible because you would hit the edge shoulders and reduce the whole edge bevel before you hit the very edge and got it sharp.
 
SuzukiGS750EZ said:
Do you think i would notice any chipping on a 5/32" 01 4" blade? All angles are the same on it. The most id do would be chopping into green trees or chopping branches off of a dry piece of wood to delimb for a walking stick. I don't baton, and if i did it would be just to make kindling wood for a fire, nothing huge. What do you think would deform the blade? So i guess what i did was a good thing on my part then?
Click to expand...

difficult to say. hardness and heat treat will be bigger factors. if you find it deforms/chips you can always redo the edge at a more obtuse angle. but i wouldn't worry too much.

SuzukiGS750EZ said:
Oh, and now it splits hair, where as before it didnt. Did the change in the back bevel really make that much of a difference to the initial edge?
Click to expand...

yes, absolutely. but i think a backbevel would be if you kept the edge at 40 degrees then knocked the shoulder off at 30 degrees. what you have done is change the angle of the primary grind.
 
FlaMtnBkr said:
You better return it back to the original edge angle ASAP before it falls apart!

I don't understand everything you are asking especially the 1/4" part, but really no one can answer any of these questions without using the knife. Which is what you should do and you will find out how the edge holds up. You can't do anything about it now so use it and see how it holds up. If it does seem delicate then just start sharpening at 40 deg again but any quality knife should be able to work well at 30 deg unless you are hitting rocks and metal with the edge.

And there really is no way of knowing what angle you have sharpened it at. If you want to know get a micrometer and use some trig to figure it out. But to my knowledge you can't put a microbevel on a knife that is more acute than the edge bevel. So 17 deg with a 15 deg edge is basically impossible because you would hit the edge shoulders and reduce the whole edge bevel before you hit the very edge and got it sharp.
Click to expand...

i think i may have misunderstood that post as well.

your edge is between 30-35 degrees. but this is just a guess based on the angle at which you now sharpen relative to the stone settings.
 
I was just going to suggest to go back to the 40* setting if you're worried about it and establish a 40* microbevel. Should be no problem at all from what you've described. I have no idea what your uses are but 40 or 30 degree inclusive, with good steel, should work just fine.

What you're doing now sounds kind of like a pain in the backside - trying to guess angles on a sharpmaker by tilting the blade. Make up your mind on one, throw it in the SM and "go for it" would be my advice. :)
 
Here is what it's looking like. The first picture is the normal 40* hold, second is the hold i do for my new edge, about that, i usually do a pass and then adjust. The last pic is obvious... lol. Thanks for all the explanations guys, i just know the standard 30 and 40, havent gone by anything over that. the 15 per side angle only hits the bottom like mm or so of the edge. The angle of the cutting edge is about the thickness of a few pieces of paper. The second picture, the knife isn't sitting on the stone, like i said, it's maybe a 1/4 to 3/8 between the stone and spine of the knife.

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Unless you're hacking tree roots out of the ground 20 degrees per side is more than thick enough.
I normally don't have edge trouble until I go below 10 degrees per side.
 
I sometimes take a folder or small fixed blade(under 6" blade) down to 15.
It will slice a little better, and feel alot sharper, but also won't hold an edge quite as long as with 20 per side. I dought you would even notice the edge holding differance though.

On the knife you show I would want it at 40(20 a side) myself. It gives you a tougher edge, will hold it longer, and you can still get a knife screaming sharp at 40.

I'm sure its heat treat was done well, and 15 per side will be fine. If thats what you like best I would go with it. It can take it, and it all comes down what you want.
 
I've seen people take O1 down to about 12 degrees inclusive and still be ok. You should be fine with 15/side. It all depends on what the use is. I used to cut sheet rock with a Schrade peanut layed flat on a slack sanding belt with no chipping.
 
I usually do around 10 - 12 deg per side with no problems at all with 52100 or O1 in the 4 inch range. And I use them pretty hard.

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They all have microbevels a couple of degrees more, I've never had any problems with durability. YMMV.
 
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