Benchmade sharpening angle?

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A month or so ago I sent in my BM 941 to be sharpened with their Lifesharp service. I had asked in the letter I sent w/ the knife if BM could change the grind angle to 30 or 40 degrees. My knife just returned, and it is very sharp (thanks BM!) However, they included a note saying that they can only sharpen at a "preset 30 degree angle on each side."

Does this mean that my BM 941 has a 60 degree edge, and is therefore too obtuse for the sharpmaker? Does anyone here sharpen their BM's on the sharpmaker?

Thanks!
Mark
 
I sharpen my Benchmades on a Sharpmaker. But, I don't use their service, so that probably doesn't help much.
But it did bump your thread.
 
I sharpen my BMs on the 40 degree slots with no problems, in fact my BM615 and 930 are the two sharpest knives I own. However I have been having problems with the 710, I might just send that in for the life sharp service.
 
30˚ on each side? I doubt that. It's probably 30˚ inclusive.
 
30˚ on each side? I doubt that. It's probably 30˚ inclusive.

I think so, too. I've never gotten a Benchmade that was 60 deg incl. I think they mean 30 deg incl. That would fit with the newest ones I've gotten from BM. Those all touch up on my Sharpmaker with the 30 deg slots.
 
I think it's actually a 60 degree inclusive...I found this describing their field sharpeners specifically for their knives:

" Here are two sharpeners by Redi-Edge® that are small enough to sit unnoticed on a keychain, or tethered around your neck. Both have a 60-degree inclusive angle (often referred to as a 30 degree angle) that will easily touch up the edge of your blade anywhere, anytime without removing unnecessary blade material. The larger sharpener also has an area for honing as well as a V-notch to sharpen fishhooks or anything small and pointy."

http://www.benchmade.com/products/product_detail.aspx?model=983902X

Not sure if this means all their knives are made to this spec though.
 
I think it's actually a 60 degree inclusive...I found this describing their field sharpeners specifically for their knives:

" Here are two sharpeners by Redi-Edge® that are small enough to sit unnoticed on a keychain, or tethered around your neck. Both have a 60-degree inclusive angle (often referred to as a 30 degree angle) that will easily touch up the edge of your blade anywhere, anytime without removing unnecessary blade material. The larger sharpener also has an area for honing as well as a V-notch to sharpen fishhooks or anything small and pointy."

http://www.benchmade.com/products/product_detail.aspx?model=983902X

Not sure if this means all their knives are made to this spec though.


That is just that field sharpener. The knives are not even close to 60 degrees inclusive.
 
I like to know the final answer as well. Given the data point of their field sharpening being 60 degrees inclusive and the original posters comment about the note they sent him "preset 30 degree angle on each side." .. To me it seems as though the factory standard is 60 degrees inclusive. ?
 
A month or so ago I sent in my BM 941 to be sharpened with their Lifesharp service. I had asked in the letter I sent w/ the knife if BM could change the grind angle to 30 or 40 degrees. My knife just returned, and it is very sharp (thanks BM!) However, they included a note saying that they can only sharpen at a "preset 30 degree angle on each side."

Does this mean that my BM 941 has a 60 degree edge, and is therefore too obtuse for the sharpmaker? Does anyone here sharpen their BM's on the sharpmaker?

Thanks!
Mark

If you have a Sharpmaker just put a little magic marker on the edge and give it a swipe or so at the 30 degree angle and see where it is removing material.
 
30˚ on each side? I doubt that. It's probably 30˚ inclusive.

Unfortunately from my experience in the past year, I do believe that it is a 60 degree inclusive angle with their lifesharp service.

In the past 1/2 year, I've received three knives from lifesharp with just such an angle.

The first was a BM710 that I sent in for servicing. It was sent with a mirror finished edge with an inclusive edge angle of about ~28 degrees. It was returned with a 60 degree angle finished with a very rough grit (rougher than my DMT XXC) and a giant burr.

The other two knives were purchased from owners that just had the knives returned from lifesharp (a BM750 & something else which eludes me at the moment) A similar obtuse angle existed on these two blades as well.

If my experience is in fact indicative of their current lifesharp service, then I would say avoid it at all costs. To the OP, yes the edge will need to be thinned down for it to hit the preset sharpmaker angles.

-Scooby
 
curious, anyone ever find out? 30 degree inclusive means...15 each side? 40 inclusive means 20 degree each side...right? newb questions...
 
Those Spyderco fanboys sure are easy to spot. :eek:

I just checked 2 brand new Benchmade knives using a digital micrometer and some trigonometry and they were 33 and 35 degrees inclusive. Should work fine on a Sharpmaker as they come from the factory but I don't have an example from their life sharp service.
 
My last 2 Benchmades have very tiny and steep bevels.

I think it could be 60* bevels and so long as both sides of the bevel are perfectly mated, you're going to have a sharp blade. Seems right anyway?
 
My last 2 Benchmades have very tiny and steep bevels.

I think it could be 60* bevels and so long as both sides of the bevel are perfectly mated, you're going to have a sharp blade. Seems right anyway?


The knives I measured looks like the edge bevel is very thin or 'tiny' in the direction of the width (height?) of the blade. But the thickness of the grind is thin enough that the actual geometry of the blade has an edge angle of 33 and 35 degrees inclusive. Just looking at how thin it was I thought it was going to be a steep angle but that wasn't the case.
 
The knives I measured looks like the edge bevel is very thin or 'tiny' in the direction of the width (height?) of the blade. But the thickness of the grind is thin enough that the actual geometry of the blade has an edge angle of 33 and 35 degrees inclusive. Just looking at how thin it was I thought it was going to be a steep angle but that wasn't the case.

I have no doubt about your post FlaMtnBkr. :)

I think it could be 60* bevels and so long as both sides of the bevel are perfectly mated, you're going to have a sharp blade. Seems right anyway?

I probably wrote this incorrectly, but I meant even very wide bevels 50 ot 60 dgrees should (theoretically) be very sharp if each side is done exactly the same. That would still give a sharp edge right?
 
Sure you can have a 60 degree edge shave great and be sharp. But it's not going to cut through material all that great because it is going to act as a wedge.

And I'm not saying that your knives can't be 60 degrees either. Just saying that sometimes they will look thicker than they actually are. I have measured quite a few Benchmade knives and have not come across one greater than 40 degrees that I remember. Sure a thick edge is possible, but I think a worker would have to be having a pretty bad day for it to happen.

I haven't seen every knife Benchmade makes, I have probably only handled a fraction of the models they make. But my comments are made based on the couple dozen knives I have owned or handled and just has been my experience so far.
 
an edge can split hairs at 60° inclusive.

i sharpen most of my knives on edge pro, it's not the most accurate way to get a precise angle but i've yet to see one that doesn't need a fair amout of time to rebevel to 15°/side. my 930 was above the 24° setting (laid flat on the flat above the grind) that's the only one i bothered to find the stock angle.
 
Axes and cleavers don't even have 60 degree inclusive bevels. My Benchmades needed a little reprofiling to get them to fit the 30 degree setting on my sharpmaker. I wish someone made cheap goniometer to measure blade angles with a reflected laser beam bounced onto the inside of a ring marked out in degrees. I could probably cobble one up, but I don't need another project at the moment.
 
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