??? For Joe Talmadge

K

KnifeDude

Joined
Aug 11, 1999
Messages
230
Joe I have often seen you post that you think that the Benchmade knives come with a edge that is too thick. Can you explain this a little better for me? I am not sure if you mean they should have a edge that is wider or narrower.

Thank You

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Knives everywhere, oh what a wonderful sight.
knifedude_@hotmail.com
 
I'm not Joe, but I think I can explain it. As you keep using and sharpening a knife the edge gets thicker and the secondary bevel gets wider. Eventually the edge gets so thick it seriously impairs cutting and you have to do something about it -- regrind primary bevel, grind a third bevel between the primary bevel and the secondary bevel, or I suppose some people buy a new knife....

Some knives come with too thick an edge straight from the factory.

How thick is too thick? It depends on what you use that knife for. The edge should be thick enough so it doesn't break and no thicker; the thinner it is the better the knife will cut.



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-Cougar Allen :{)
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This post is not merely the author's opinions; it is the trrrrrruth. This post is intended to cause dissension and unrest and upset people, and ultimately drive them mad. Please do not misinterpret my intentions in posting this.
 
I'd better explain those terms: the primary bevel is the bevel from the thickest part of the blade down to the edge. The secondary bevel is the one you sharpen when the knife gets dull.

Joe's favorite way to thin the edge is to grind a third bevel between the primary and secondary bevels. I usually prefer to regrind and repolish the whole primary bevel. My way takes longer but doesn't have to be done as often.

-Cougar :{)
 
With a new knife it is sometimes as simple as needing to use a different angle when sharpening too. Sharpening with the blade at say a 35 degree angle to the stone would make the cutting edge really wedge shaped and inhibit its cutting ability. Sharpening at a 15 degree angle makes the edge very thin, better slicer, weaker edge.

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Fix it right the first time, use Baling Wire !
 
With Benchmades, I think there are two separate problems.

The first is that the edge bevels are ground at just too high an angle. By my reckoning, 25 degrees or more, which is an angle I reserve for knives that take serious edge punishment, not for my folders. I want my folders to cut, so I like 17 degrees-ish, 20 degrees max.

The other is that the edge does seem thick. When the blade gets sent off for heat treat, the knife isn't sharpened all the way yet, because a very thin edge will have problems in the heat treat. Maybe Benchmade leaves the edge a bit thick, and doesn't grind it off when doing the final edge.

As Couger pointed out, my favorite way of thinning the edge out is to grind an intermediate bevel. So I'll grind a 15-degree thinning bevel, and take that to within 1/32" (or more often, 1/64") of the final edge. Then I'll throw a 20 degree bevel on top of that. The result is a nice thin edge, which *seriously* outperforms the factory edge, but which is still strong enough to hold up to what a folder needs to do.

Joe
 
Just to echo what Joe says about the edge angle of Benchmade knifes, I used my laser-pointer on the edges of my new BM 705 and 710 knives (a method I mentioned on a post some time back which measures the total deflection angle of the beam).

The 705 measured at 49 degrees and the 710 was 57 degrees at the front, 51 degrees at the rear recurve. These are total included angles, so the edge angle should be roughly half of that (assuming the angles are symmetrical ... not always a given), so that jibes with Joe's "reckoning" of 25 degrees.

Since I haven't found a good way to calibrate my measuring method, it remains nothing more than another "reckoning", just so no one takes my numbers as hard fact.

By contrast, my 4 Spydercos measured mostly at between 31 and 33 degrees, with one at 43 (must've been a newbie at the factory), so the average edge angle for them appears to be a bit over 15 degrees.

Might be a coincidence, but the "wide" Spydie was a SS Dragonfly in ATS-55. BM's I tested were all ATS-34. Maybe the wider angle offsets a possible tendency of the steel to chip? (ATS-34 and ATS-55 are close cousins).

My Spydercos are correspondingly sharp out of the box compared to the BM's, tho I'll add that I don't shave enough hairs to worry about redoing the BM edge.
 
Originally posted by Longden:
Just to echo what Joe says about the edge angle of Benchmade knifes, I used my laser-pointer on the edges of my new BM 705 and 710 knives (a method I mentioned on a post some time back which measures the total deflection angle of the beam).


Longden
Can you give me a keyword and forum to search out this Post?

thanks,

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Roger Blake
Click to expand...
 
Thank you Joe and everyone else
wink.gif


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Knives everywhere, oh what a wonderful sight.
knifedude_@hotmail.com
 
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