Why would my Benchmade knife have such poor edge retention?

[Garrett Stephens]

I have a Benchmade Barrage with S30V Steel and it seems like it has poor edge retention now. I need to sharpen it basically every week or two with minimal use. When I first bought it, it had the factory edge (which was literally razor sharp and stayed that way for a long time), then I did not have a can opener, so I cut a aluminum can open with the knife (which it did flawlessly with no damage except dulling), then had it professionally re-sharpened by the store I bought it from (who is a certified Benchmade dealer, and says that they can put a factory edge on it), it is never as sharp as the original factory edge, nor is the edge retention as good. Now regarding it is not as sharp as the original facory edge, that has an explaination, he claims that he sharpens so many knives that he doesn't have time to do special edges or super sharp edges that a lot of people request. Even my Buck 119 knife and my $10 Home Depot knife has better edge retention currently than my Benchmade Barrage. The professional knife sharpener also told me that the sharper that you make a knife the weaker the blade will be and so not putting a razor edge on it is a compromise between strength and sharpness.

Ever since cutting that can, I have had such poor edge retention that I simply open a few boxes (cutting the tape, not the cardboard) and cut some paper (in testing) and whatever sharp edge it had from sharpening goes away almost instantly.

I used the Lifesharp service one time and they did not get it as sharp as the original factory edge, and nor did it solve the issue of the edge retention. I had some guy at a local gun show sharpen it recently and that has had the best results so far. I went 3 weeks of mild use (instead of one week) before the "razor edge" went away.

I bought the knife specifically because it is a Benchmade (which have very good knives), and because it is made of S30V (which is very good steel). I know that S30V is not designed to have a razor edge like S110V or 420HC is, however, it had a razor edge from the factory. I see YouTube videos of people who take a Benchmade knife made from S30V and they are able to cut 200+ pieces of cardboard before it will stop removing hair from their arm. The original edge that I had would have been able to do that, but the current edge is one piece of cardboard before it will remove hair if the professional sharpened it sharp enough to do so in the first place).

I would sharpen the knife myself, but I lack the fancy equipment and only have a wetstone to sharpen it with. Did I get a bad blade, did the can damage it beyond repair, or is S30V not that good of steel?

 

[SuzukiGS750EZ]

If you turn the edge up in the light and move the blade to get the light to hit different parts of the edge, do you see shiny? I would say invest in your own sharpening system and do it yourself. Maybe something guided? Spyderco sharpmaker? Edge pro? Wicked edge?

 

[Garrett Stephens]

If you turn the edge up in the light and move the blade to get the light to hit different parts of the edge, do you see shiny? I would say invest in your own sharpening system and do it yourself. Maybe something guided? Spyderco sharpmaker? Edge pro? Wicked edge?

Thank you for your reply. What would a shiny vs. a non-shiny edge tell me?

Yeah, I plan on investing in my own sharpening equipment. I just cannot invest in it right now since. I know that long-term, investing in my own sharpening equipment will save me time and money since I don't have to spend $2 every week or every other week to get my knife sharpened. It adds up. I certainly appreciate the recommendations of different equipment options to choose from. I don't know much about modern knife sharpening. I am a Fudd and use a wetstone, but that doesn't work with modern super steels.

 

[AntDog]

$2? Lol, who’s sharpening your knife? Pa Kettle at the back of the Ace hardware?

Anyway, I freaking love Benchmade’s S30V. I have a Presidio in that steel. I sharpen it on my Sharpmaker (to razor sharpness) and it holds the edge a very long time.

Something is wrong here if it won’t hold an edge. And anybody who says they won’t sharpen a knife to razor sharpness because it weakens the knife or whatever cop out has no business sharpening knives.

 

[Garrett Stephens]

$2? Lol, who’s sharpening your knife? Pa Kettle at the back of the Ace hardware?

Anyway, I freaking love Benchmade’s S30V. I have a Presidio in that steel. I sharpen it on my Sharpmaker (to razor sharpness) and it holds the edge a very long time.

Something is wrong here if it won’t hold an edge. And anybody who says they won’t sharpen a knife to razor sharpness because it weakens the knife or whatever cop out has no business sharpening knives.

Thank you for your reply.

Lol. No it is not Pa Kettle. One guy in town charges $2 and the other guy in town charges $6. I do live in Idaho, so I don't know if that is why or if they are super janky. The guy who charges $6 owns an actual, reputable store in the area and does knife sharpening as well. The guy who charges $2 just sharpens knives, chainsaws, hand saws, axes, etc.

That is good to know that Benchmade has really good S30V. That is what I thought when I first chose the knife/steel that I did. Before that, I was used to 8CR13MoV steel, so I knew that S30V would be a significant upgrade, and it was an upgrade until it stopped holding an edge for some reason. Maybe I need to pay the $40 to have my blade itself replaced.

Maybe I should invest in my own sharpening equipment since the two local sharpening services are "cop outs".

 

[PirateSeulb]

I don't know why their services are so cheap but they are both fairly under priced for what I have seen around the web and locally for sharpening service.

The professional knife sharpener also told me that the sharper that you make a knife the weaker the blade will be and so not putting a razor edge on it is a compromise between strength and sharpness.

This I would say is a half truth at best the more acute the edge is the less material there is to support it so it is typically easier to roll or chip such an edge. The shiny/light check mentioned above is to help spot rolls as the light will hit spots differently where the edge is different again simple science at work there too. The geometry of the edge is very important to the longevity of the edge but so is the use of the edge so how often you cut and the material being cut will greatly impact the life of the edge. If you have started using it more or using it more on material that is tougher on the edge it will also result in an edge that dulls faster.

Some general edge ideas for longer lasting edges are convex tends to be a more stout edge but often not as "sharp" than a V grind or Hollow grind with Hollow being the "weakest" edge. Depending on the need you won't need to sharpen it to a razor edge you might be better served by a more obtuse angle that will be stronger and longer lasting but will likely not feel as sharp to the touch.

I hope I am not misleading you and if I am hopefully one of our pros will step in to correct me and clarify anything I have confused you on.

 

[Bluemantra]

How are these people sharpening your knife? Free hand, a guided system, grinder?

 

[Garrett Stephens]

How are these people sharpening your knife? Free hand, a guided system, grinder?

Belt grinders only.

 

[Bluemantra]

There can be a lot of variables involved, but my bet is the belt grinders are the reason why your edge retention is bad. Pay someone to sharpen it on stones via a guided system or free hand. I know it's been said, but the best thing for you to do is to do it yourself, but I see you are planning to do that.

 

[Garrett Stephens]

There can be a lot of variables involved, but my bet is the belt grinders are the reason why your edge retention is bad. Pay someone to sharpen it on stones via a guided system or free hand. I know it's been said, but the best thing for you to do is to do it yourself, but I see you are planning to do that.

Thank you for your reply. Why would belt grinders cause the edge retention to be bad?

What stones do you recommend for sharpening S30V?

 

[Bluemantra]

Thank you for your reply. Why would belt grinders cause the edge retention to be bad?

What stones do you recommend for sharpening S30V?

This may be something similar to what you're experiencing;

 

[Bluemantra]

Grinders can cause fatigued steel.

 

[AntDog]

Grinders can cause fatigued steel.

And a burnt wire edge that will cut a few days, then break off and be dull (which might be what is going on here).

 

[Silent H]

Thank you for your reply. Why would belt grinders cause the edge retention to be bad?

What stones do you recommend for sharpening S30V?

I have used a Spyderco Sharpmaker for several years now, and have never had an issue keeping any of my knives sharp, but that was mostly for maintaining slightly dulled edges.

You're probably going to want to remove a little more material and reprofile your edges to get past the burnt and fatigued edges from the belt grinders. Diamond stones will make that much easier. I recently got the Worksharp Precision Adjust sharpening system, and I am getting my knives far sharper than I ever thought I could. It's a guided system, super easy to use, and a very reasonable price compared to some of the other guided systems on the market. It comes with two diamond stones with different grits, and a ceramic stone. It can handle any steel you put on it.

 

[Babyboomer]

We had a local Benchmade dealer (now sadly closed) who had a Tormek behind the counter. He charged $7 to sharpen a Benchmade, figuring that it was a service he should offer and that it would cost about $7 to ship a knife to Benchmade for their free sharpening. Did a great job and he had the leather wheel to strop it. Whenever I bought a Benchmade there I’d have him improve the edge before I left with it.

Miss that place.

 

[Bluemantra]

Not about S30v specifically, but I think drives home the effects a burn edge can have on performance and the importance of sharpening your knives.

 

[marrenmiller]

Learn to sharpen your own knives with a stone/strop and don't let people put edges on yours with belt sanders. Belt sanders are fast but take a lot of steel off your knife and heat up the edge, which will result in crappy edge retention. Don't send it to Benchmade either, as they sharpen with a belt sander.

What's most likely happening here is that you've just had a bunch of bad edges, simply put. If you sharpen your own knife, you can learn a new skill, save some money, and guarantee a better edge on your knife. I'd recommend getting some diamond plates.

 

[Gil P.]

The dual sided Venev stones will be the most cost effective. The 400/800 will get you good edges and be sufficient for sharpening dull edges. I'd get something coarser if you need to reprofile or repair a damaged edged.

 

[me2]

Belt grinders only.

There’s your issue right there. IF the people sharpening don’t have some sort of coolant on the belts and/or run the belts at very low speed, they’re almost certainly overheating the edge. Dipping the blade in water after every pass doesn’t count. Now, if they are only shaping the edge then finishing on stones, it’s much less likely overheating is the problem. The over heated part might extent 0.003” to 0.005” into the edge, so hand sharpening afterward would likely remove it. I used to sharpen a lot with a belt sander and stopped because of this issue. I still rebevel and repair sometimes, but final sharpening is by hand. Send it to Josh at Razor Edge Knives in South Carolina. He used cooled systems and hand sharpening with guided systems. He’s a bit more expensive though. He has a forum here.

 

[Lodd]

And a burnt wire edge that will cut a few days, then break off and be dull (which might be what is going on here).

You should hope so. The wrong belt grinder can ruin the heat treatment, permanently ruining the knife. Unless a belt grinder is specifically suitable for sharpening knives, it is not for sharpening.

Another common mistake around here (Edit: By which I mean the Netherlands) that ruins knives is the use of the spinning stone wheel (I forget the exact english term). That'll mess up your knife right quick.

I hope OP got spared the permanent damage.

This is a perfect example of why cheap is often more expensive.