The Most Incredible Knife Sharpener I Have Ever Used

[Azula Gun Holsters]

I have tried many knife sharpeners over the years and have found that the clamp system had always worked the best. Gatco, KME, Lansky and Wicked Edge all did a good job on the small knives but it became a bit of an ordeal to sharpen the big knives. The clamps would struggle with the bigger and thicker knives and it took forever to re profile a knife. Was never overly happy about pushing the stones into the edge. If you got tired or sloppy you would get cut.

Saw a post on IG where a knife maker was using an AMK-75 knife sharpener to get his knives razor sharp. There was very little online info about the AMK-75 sharpener.

I got the chance to use the AMK-75 and it is the most incredible knife sharpener I have ever used. It took a mere 15 minutes to get a razor sharp edge on a big Busse knife. I adjusted the edge to 20 degrees per side. Started with a 130 belt for a few passes. then a 220 belt, 800 belt, 1000 belt and finished with a leather strop belt and green compound.

The usual clamp for the AMK-75 is a single clamp but they also make a custom dual clamp for bigger and thicker knives. The dual clamp works very well for big knives like the NMFBM and even works well on a medium knife like a Boss Jack.

It really is amazing how fast the AMK-75 can sharpen a knife with a consistent screaming sharp edge. All the following edges are at 20 degrees per side. You really have to be careful handling the knife as they are very very sharp.

The AMK-75 is very well made and made in the USA.

AMK-75 WITH THE DUAL CLAMP AND A SCRAPYARD 1111

DUAL CLAMP ON A BOSS JACK

SINGLE CLAMP ON A RODENT 6

VERY SHARP EDGE ON A SCRAPYARD 1111

VERY SHARP EDGE ON A NMFBM

VERY SHARP RODENT 6

VERY SHARP BOSS JACK

THE AMK-75 KNIFE SHARPENER VIDEO

 

[Hard Knocks]

Thanks for sharing that. I don't believe I've seen or even heard of that sharpener before.

 

[duramax]

That’s pretty wild, I’ve been looking for a new serious sharpening system. But I don’t know if I’d trust myself with a belt system lol. I’ve been looking at the TSPROF wrangler star sharpener, cause it can handle large / small blades. I have various sharpeners know, include is a work sharp. But I only use the work sharp on my less expensive cutlery.
That AMK-75 peaks my interests
Thanks for sharing

 

[TommyGun56]

^^^Also Peaks my interest. Thanks for sharing your experience with the AMK-75 With Christmas around the Corner, I may have found another item to add to my "I would like to Have" List.
Question? Have you had a chance to see how it Sharpens smaller Knives? Say in the 4-5 inch range?
Thanks for taking the time to Post your results (review)

 

[Azula Gun Holsters]

I have tried the work sharp and did not like it. I could not get a consistent angle with the guides. The AMK-75 is a completely different system. The AMK-75 makes it easy to get a consistent edge without the worry of damaging your knife.
Have not tried a smaller knife yet but will give it a try in the next few days.

The the TSPROF wrangler star sharpener looks like a nice system but you have the same issue of pushing stones into the edge. It will take a long time to re profile a large knife.

 

[Bladegunner]

May purchase one of these for large and kitchen knifes. I would like to hear some feed back from anybody that has owned one for a while. Looks like all quality components I actually thought it would be more expensive.

 

[Casinostocks]

As Nathan has cautioned and mentioned several times in the past when he was asked, just be bery careful about how hot you may get the edge of your D3V steel when using belt sander sharpening methods.

 

[ice-pic]

Very interesting thanks for the review.
I use a wicked edge and it is a struggle with big knives,like extra clamps and screw jacks to support the knife to keep it stable.
I will look into this AMK-75.

 

[Bladegunner]

Very interesting thanks for the review.
I use a wicked edge and it is a struggle with big knives,like extra clamps and screw jacks to support the knife to keep it stable.
I will look into this AMK-75.

I agree, With this system and my WE I think I would have all bases covered.

 

[CPK Mark]

Uncle M speaks truths. It can be very precarious sharpening with a power grinder. Wetting the belt makes a big difference. We run our machines slow and belts wet for sharpening. I can sip my beer twice before the belt makes a revolution

 

[Grenock]

Very interesting. Thanks for the heads up. The fact that it is a variable, down to about 1,000 rpm according to the video I watched, I would think you can keep the heat down so it would work with our beloved D3V. You are also in complete control of the down pressure, so again, I think keeping the heat down would be possible. Seems as though it would be very accurate and repeatable as far as you angles go.

On another note, damn! Why is the good shit always so expensive?

Edit: Read what Mark wrote, maybe it is still too fast. Damn, 1/2 RPS(revolution per sip), that is slow. I'd be drunk by the time I finished sharpening a BC

 

[Tim the Wizard]

Very cool. Something funny going on near the tips though.

 

[Nathan the Machinist]

Yeah I get real nervous about people putting our knives to powered sharpeners. Our reputation is based upon our edge retention and this can be harmed by powered sharpening. You won't notice any heat out in the blade and the edge will have cooled by the time you can touch it and you'll think you're not hurting anything but the very edge (the part that actually cuts) can heat enough to loose the magic.

There isn't a good way to measure the hardness at the very cutting edge, but you could heat the edge up to 500 very easily.

Powered sharpening can be done dry but only at very low speeds, moderate pressure and keep things moving. We sharpen wet but we're also removing much more material on the first sharpening than a re-sharpen. If your speeds are no faster than manually sharpening on a stone you're okay. If you see sparks you're definitely not okay.

 

[Grenock]

Yeah I get real nervous about people putting our knives to powered sharpeners. Our reputation is based upon our edge retention and this can be harmed by powered sharpening. You won't notice any heat out in the blade and the edge will have cooled by the time you can touch it and you'll think you're not hurting anything but the very edge (the part that actually cuts) can heat enough to loose the magic.

There isn't a good way to measure the hardness at the very cutting edge, but you could heat the edge up to 500 very easily.

Powered sharpening can be done dry but only at very low speeds, moderate pressure and keep things moving. We sharpen wet but we're also removing much more material on the first sharpening than a re-sharpen. If your speeds are no faster than manually sharpening on a stone you're okay.

Yep, too fast then.

Natoscopic eta carbides? Seriously?

 

[Nathan the Machinist]

yeah when I first posted that "nanoscopic" autocorrected to nato scopic. lol

 

[on_the_edge]

Yeah I get real nervous about people putting our knives to powered sharpeners. Our reputation is based upon our edge retention and this can be harmed by powered sharpening. You won't notice any heat out in the blade and the edge will have cooled by the time you can touch it and you'll think you're not hurting anything but the very edge (the part that actually cuts) can heat enough to loose the magic.

There isn't a good way to measure the hardness at the very cutting edge, but you could heat the edge up to 500 very easily.

Powered sharpening can be done dry but only at very low speeds, moderate pressure and keep things moving. We sharpen wet but we're also removing much more material on the first sharpening than a re-sharpen. If your speeds are no faster than manually sharpening on a stone you're okay. If you see sparks you're definitely not okay.

It sounds like a real potential for the phrase "haste makes waste" to come true. I'd hate to see someone try something new like this thinking they were doing fine only to discover that their CPK knife no longer performed the way it previously had despite being seemingly very sharp. It would be even worse if such knives started finding their way to the secondary market. I think I will just keep doing mine by hand on unpowered sharpeners. I'm a patient guy anyway.

 

[Hard Knocks]

You won't notice any heat out in the blade and the edge will have cooled by the time you can touch it and you'll think you're not hurting anything but the very edge (the part that actually cuts) can heat enough to loose the magic.

I moved away from finishing on power hones, i.e. paper and leather wheels with compound for the same reason, even on non-d3v blades. I can get them screaming sharp but they dull very fast when using that method (compared with stropping by hand). I've come to believe it's the flash heat along the edge that's the culprit.

 

[Nathan the Machinist]

Oh yeah, those paper wheels can be terrible. I'm not saying it isn't possible to get good results with something like that, but anything that is spinning screaming fast is going to burn your edge a little.

Rather than duplicate my thoughts this was my response to a burned edge argument over on USN a while back:

It wouldn't surprise me if many (most?) custom makers who sharpen a lot of knives dry occasionally have areas of at least slightly burned edges and don't know it.

It's simple. If you take two identical knives in an alloy like S30V and grind one edge dry (be a little bit sloppy with your pressure, feed rate and belt sharpness, you're looking for a worst case but potentially plausible version of your normal process) and grind the other edge in slow and wet, then sit down with both and whittle some wood for a little while then look at the edge under light and magnification. When I did this the difference was very clear and unambiguous. Obviously the angle has to be closely controlled, not just eyeballed, for a meaningful comparison and a reasonable angle (obtuse edges don't burn as badly). If a maker hasn't done this simple thing their opinion on the subject really isn't very informed. I've done it and I changed my process because of it and I'll bet I sharpen more knives in a year than most folks here.

I just did a little bit of math looking at a theoretical blade of these dimensions:
FFG, .150" at spine, 4 DPS primary grind angle, 15/16th blade height, .025 BTE, sharpened 18 DPS

The sectional area is .0786877

The sectional area of the edge .005 back from the edge is only .000008123.

That gives a mass ratio of the blade to .005 of the edge of 9687:1. That's a lot of orders of magnitude difference. If you were to instantaneously raise that .005 of edge area by 1000F then let it equalize into the blade it would raise the temperature of the entire section by only 1/10th of a degree.

In practice it isn't instantaneous but this illustrates why making judgments about the temperature of some very small area that is some distance away from your finger tips based on the temperature your fingers feel isn't very accurate.

I'm not trying to be argumentative or snarky here. Some people manufacture knives that are expected to have very good edge retention out of the box and others may make knives where it really isn't that big of a deal so long it's just a few thou near the edge that is affected and it still works reasonably well. There are all kinds, and that's great. But I wouldn't dismiss something that is so easily verified just because your own experience hasn't shown it to you.

All of that said, S30V is not rocket science to sharpen on powered equipment and get it truly sharp with a quality edge. It is simply not a big deal. Unless you're burning the edge trying to sharpen it. Which people do. Then you can get this exact situation.

 

[KooKooforKukripuffs]

I just use my 1x30, I don't need a guide to sharpen a blade, all it takes is a decent eye and a fairly steady hand. 120 if needed, 400, 600 and 1000.

 

[Casinostocks]

Not to hijack the thread, but some thoughts regarding the W.E. guided system hoping that user's of this system can chime in:

I know that adding the extra accessories can become expensive fast and that some of the offered accessories may not bode too well with the more basic and the older systems but would acquiring the Gun 3 jaws for up to 0.25" knives plus a 12" guide rod instead of the stock 10" guide rod not help in most cases? I have never owned a Busse made knife but I do understand that in some cases the Busse stock is > 1/4" which will be problematic for those thicker Busse's but as far as CPK goes, short of the original Proto-HC, I am not aware of anything else thicker > 1/4". Before the BC (Big Damn Knife) which has a BL of 12", there was nothing else > 10" and if Nathan decides to go 0.260 vs 0.250 with the HDMC, that will also become problematic but I think that Nate is going 0.250 IIRC.

What am I missing?!