Using diamonds on 'soft' stainless steels

[maximus83]

Recently some folks have reported that when using diamonds on softer stainless steels, the experience is like "butter", the steel is "gummy" on the stone, the diamonds will leave too deep scratches in the soft metal, etc.

I haven't done any exhaustive testing with diamonds on many types of softer stainless, but I have started testing using diamonds on a few soft stainless steels I have in folders, and kitchen knives. Two I tried this evening: 420HC (Buck's HT) as in a Buck Selkirk folder, and some Chinese 7Cr17MoV stainless in a beater S&W 602 folder that I use for practice. With both knives:

• Reprofile edge to about 14-15 dps on Atoma 140
• Apex and finish on DMT coarse, no strop

Neither of these 2 knives experienced the issues I've heard described. The Atoma cuts clean, consistent, and fast and actually leaves a pretty good edge itself. In the case of the S&W 602, this knife was a mess from the factory. The edge bevel was incredibly unevenly ground on one side, I don't even think angle was the same. The blade was so bad there was a small visible recurve (but clearly unintentional--based on retail site pics) back near the heel. Using the Atoma and some heavy grinding, I was able to totally repair and reprofile that edge, remove the ugly recurve, and get the thing to a fairly clean consistent bevel in about 20 minutes of work. Then with the coarse DMT, started with heavier slices to reset the scratch pattern from the Atoma, then at the end super light passes to reduce burr. At the end, both knives off the coarse stone could push-cut newsprint slashing entire chunks off, and shave arm hair. They both have a visibly toothy edge and won't win any beauty contests in the polished edges thread , but this is a good utilitarian edge just from working them off of coarse plates.

Pics of the S&W 602

* After the Atoma edge reprofile. You can see the high spot back near the heel, I had to go up that high on that one side to get their uneven grind back to a consistent edge bevel. At first their ground-in unintentional recurve was so bad I had trouble getting that part of the blade on the stone.

* After the DMT coarse

No grand conclusions, my test size isn't big enough. But it does seem like diamonds worked great on these knives.

ETA: I went back later and refined on DMT EEF. That worked great too. Basically I have no plans to sharpen a lot of my softer steels on expensive diamonds and wear them out sooner than necessary. Just wanted to prove to myself whether it would work well.

 

[Wowbagger]

Using diamonds on 'soft' stainless steels

I was going to say "Nah dude, nah" but if it is working for you then THAT IS ALL THAT MATTERS.
Personally I just hate using diamond stones and only use them for the high vanadium steels because I have to.

I AM glad you have stones that are working well for you. Thanks for the thread.

 

[maximus83]

Put it this way: we all have preferences, I still prefer my Arctic Fox to the feel of diamonds too.

But...you still want to have one stone type that you know can handle every steel you have. For me, say backpacking, I only want to bring one type of sharpener regardless what knives I bring. I just want to demo/confirm for myself that my diamond abrasives actually work well on all the steels that I have. I don't have any other candidate for "universal abrasive" besides diamonds.

 

[Alberta Ed]

I've found that diamond hones work great on softer "kitchen" blades.

 

[Jason B.]

It's all in perspective.

If you only use diamonds regularly then you will overcome or not even notice these issues. If you use many different stones and consistently sharpen the same steels you will start to see the difference. It takes a lot of comparison between stones to start seeing a difference in the steel.

For me, I use waterstone on softer steels because I feel they produce a better edge with less distortion to the edge and scratch pattern when compared to diamond abrasive.

 

[Obsessed with Edges]

If I'm reading the OP correctly, I completely agree there isn't much significance to the notion that diamonds are somehow not suited to softer steels; or worse, that diamond hones can somehow be damaged by softer steel. That's an issue of defect in manufacturing or in not knowing how to use them properly, with regard to pressure applied.

I've liked a diamond hone for certain kitchen knives, just because I can utilize it to quickly produce a certain 'bite' in the edge that works great for some kitchen uses; and it gets it done so freakin' fast, with minimal effort. Just a handful of passes on a Fine or EF diamond hone, and the edge is completely restored and done in a minute or two, with no mess. It's just plain simple, and it works great. That's what I like about it.

In terms of edge finish, I can see some steels being more responsive to specific abrasives. There are just some steels that like certain stones, and some stones that like certain steels. When I'm willing to take a little more time to tweak an edge to a certain finish on simpler and 'softer' steels, a combination of an aluminum oxide stone (oilstone) for regrinding bevels, following with refinement on a soft or medium Arkansas stone (also used with oil) produces really nice, fine satin edges with some wicked bite. But obviously, there's a little more work involved, more gear used, and some oily, swarfy mess to clean up afterward. But it can be very relaxing to do, and also very rewarding for the effort.


David

 

[HeavyHanded]

My experience is they work fine on whatever.

I find they work no faster of budget steels than any other abrasive though, and I do notice they take more futzing around to remove the burr cleanly on gummy stainless. I really don't much like the feel of them, so unless I have a specific reason to use them over another stone, I don't.

 

[microtech85]

It's all in perspective.

If you only use diamonds regularly then you will overcome or not even notice these issues. If you use many different stones and consistently sharpen the same steels you will start to see the difference. It takes a lot of comparison between stones to start seeing a difference in the steel.

For me, I use waterstone on softer steels because I feel they produce a better edge with less distortion to the edge and scratch pattern when compared to diamond abrasive.

Jason b. Makes a point. My first two quality knives were kershaw. A whirlwind in 440a and a liner lock in aus6. My first and only sharpener i had at the time was diamond and i never noticed any problems. It got my knives sharp. I guess maybe just use the diamond stone with lighter pressure to compensate for its deeper cuts.

 

[maximus83]

My experience is they work fine on whatever.

I find they work no faster of budget steels than any other abrasive though, and I do notice they take more futzing around to remove the burr cleanly on gummy stainless. I really don't much like the feel of them, so unless I have a specific reason to use them over another stone, I don't.

Agree Martin. I haven't used diamonds a ton on 'soft' stainless, but the few times I have including last night, it seemed to me like they worked no better/faster, and also no worse/slower, than anything else I've used for just a utility edge. Of course I'm not inspecting those edges with a scanning electron microscope, so there could well be meaningful differences I'm not aware of. All I know is diamonds do seem to be able to get these steels that I own as sharp as anything else I use, and don't seem to have any nasty side effects that I've noticed.

 

[maximus83]

In terms of edge finish, I can see some steels being more responsive to specific abrasives. There are just some steels that like certain stones, and some stones that like certain steels. When I'm willing to take a little more time to tweak an edge to a certain finish on simpler and 'softer' steels, a combination of an aluminum oxide stone (oilstone) for regrinding bevels, following with refinement on a soft or medium Arkansas stone (also used with oil) produces really nice, fine satin edges with some wicked bite. But obviously, there's a little more work involved, more gear used, and some oily, swarfy mess to clean up afterward. But it can be very relaxing to do, and also very rewarding for the effort.

David

Yes, that seems intuitively right that some steels are most responsive to certain abrasives. Even if it's true that a given abrasive can get something sharp (e.g., diamonds can successfully sharpen a particular 'soft' steel), there may be another abrasive that with that same steel, produces an edge that has certain characteristics we want. It would be super interesting to me--but a firestorm of controversy I'm sure--if some experienced sharpeners around here took a stab at doing a chart trying to list "optimal abrasives for popular steels" based on their experience. I'm sure we'd have opinions all over the place on that one.

Also, I totally get the enjoyment aspect. That in particular is why I use other types of stones when I can over my diamonds, it's not even mainly because the diamonds are more $$ and I don't want to wear them out as fast. It's really because I just LIKE the feel of some kind of natural or synthetic stone materials--be it AlOx, SiC, waterstone, ceramic, arkansas, whatever--over a metallic plate.

 

[Lapedog]

My experience is they work fine on whatever.

I find they work no faster of budget steels than any other abrasive though, and I do notice they take more futzing around to remove the burr cleanly on gummy stainless. I really don't much like the feel of them, so unless I have a specific reason to use them over another stone, I don't.

Honestly I have had no luck with my coarse DMT spyderco rods. The surface feels so bumpy and the blade feels like it is skipping across the peaks of the abrasive particles.

I just cannot get a sharp edge with diamonds. I have no problem when using my ceramic sharpmaker rods. I am using very light pressure. However it seems putting my edge to those diamond rods will always result in the edge getting worse.

 

[maximus83]

Lapedog I'm just guessing as I don't know what you ran into. But as long-timer with the Sharpmaker, I agree the sharpening experience with the Spyderco diamond rods is not that great. Wondering if your issue is just with those specific Spyderco rods, not with diamond abrasives in general. The experience of sharpening on a nice diamond bench stone is very different, and enjoyable.