Anybody put a Convex bevel on their BHs?

[Soilarch]

Knife guys like to debate bevel (what we call double bevel), chisel (what we call single bevel) and a convex edge.

I don't want a debate, just want to know if anybody has tried a convex on their BHs?

[StanM]

Just to clarify for me, when you say convex do you mean the bevel is rounded out, like the opposite of a hollow grind?  I guess like an axe would be a good way to describe it.

I do not do this, I'm a single beveler.  Interested to hear what others have to say.

[FerretWYO]

Silver Flames are I believe.

[Soilarch]

Yes, like a very very acute angled axe.

I'm getting setup to sharpen the very expensive hairdresser scissors with that have a "convex" edge.

They can be done and maintained by sandpaper laid on top of a mousepad.  (I used that for a long time on knives)

[Ragnarok Forge]

I haven't done it. I gave it some serious thought and figured it would actually decrease penetration.  It works great on an axe or sword since it helps part what you are cutting into.  With a broadhead the tissue you being cut is moving along the edge instead of perpendicular to it. I don't think that kind of edge would be as effective as a razor sharp double bevel or single bevel edge

[Soilarch]

EDIT:  Dag-nabbit.  I didn't want a debate and here I am being the first to turn it into one...  

It would be every bit as sharp as any other BH.

Convexs are used in Japanese swords...and are very popular in knife cutting competitions. (Apparently we can turn anything into a competition.)  


That's what got my curiosity rolling.

[Old York]

Do you folks mean a  compound  bevel?
  :confused:


(Like on an iron plane)

[fido dog]

My hair shears are damn near $400 (yes I can cut hair also). I sure would be interested in the sharpening process to save me 35 bucks...LOL!

I'm sure with a super fine edge that they would slice right through tissue and bone just fine. Maybe even hold that edge just a bit more? You may be on to something here.

[Soilarch]

No, not really.  (Glad someone else likes the old hand planes though!)

Here's is what we typically put on a single bevel BH    

Here's what I'm wondering about
   


....$35!!!    

[tippit]

A couple reasons for the convex edge on a knife, is to taper the bevel away from the edge so when re-sharpening all you are sharpening is the very edge.  Thus quicker and easier to re-sharpen.  It will cut easier without all drag/resistance of having to pull a wedged edge.

They are more difficult to do in that you have to grind and round the back of the edge away from the final edge...but you end up with a very fine edge.

Most broadheads have very thin steel to begin with thus the convex/taper would be very minimal and weaker IMO.  Also they tend to be tempered softer than a knife. Being softer they are easier to sharpen (remove steel) but they will have more tendency for the edge to roll.  Remember they only need to cut once as apposed to a knife that you want an edge to hold as long as possible.

For me anyway, it wouldn't be worth the extra effort to grind a convex edge which would reduce the strength of a softer edge.  That is unless you actually made the broadhead harder more like a knife (Silver Flames for one).  I will do that on my own forged broadheads.  JMHO...tippit

Convex single bevel edge on my forged broadhead that is tempered harder than most commercial broadbroads.  

 

Woody Blackwell's convex edge...by design of the maker & the material having to be rounded  

 

[Soilarch]

tippit, I agree with the points you've brought up.  I had planned to play with Grizzlys to begin with, since they are what I have on hand.  Instead of doing the Ashby proscribed 25*  I thought I'd try more along the lines of 30* to compensate for less material directly behind the edge.

I know Ashby didn't arrive at 25* by accident, but I cant help wondering if reducing the CUTTING edge angle (to 25*) is more, or less, important than increasing the "back angle" to 155* where the bevel ends.  We know 30* can be just as sharp...and by going convex, we don't give up any strength, in essence remove that 155* angle that I'm sure eats up some of your KE/Momentum.

Needless to say, I'm going to have to try it if I buy the machine.

[Butch Speer]

One of my hobbies is wood carving. All gouges are single bevel. Some very good tools have a very slight compound angle edge. These tools cut as good as those without the compound bevel but, are much stronger. These tools are tempered 60-60 Rockwell Y are sharper than any tool you can imagine. The second bevel really strengthens the edge without compromising it's sharpness & makes for a very strong edge. It's also a lot easier to do than a convex cause it doesn't need any tools more than you already have. Not saying anything bad about the convex. JMO