In my using the two I have found that S30V takes a finer edge and holds the fine edge slightly longer but D2 will take longer to go fully dull. I am crediting this to the size of the carbides but would like others opinions as to what you have found.

Gary

Gary, what hardness are you using for the two steels, and are they the same edge (i.e. angle, etc.)?

It's been a long time since I've used D2, and I've gotten a little better at this since I did, but I don't remember being blown away by the steel's capabilities as I have with S30V. I always had trouble getting a "fine" edge on D2, and was often reminded of the old adage that "D2 takes a terrible edge and holds it forever." I did my own heat treating on D2, and have Paul Bos do everything now, so that certainly makes a difference. I may not have given D2 a fair shake, though I did the best I could to follow the charts to get Rc62, but no cryo. Neither of these steels are easy to sharpen though.

Actually, now that I think on it, I really didn't give D2 a fair shake, since I used to finish my edges with more tooth than I do now. That gives it more bite, but it doesn't wear as well. I now finish edges to 16 microns and sometimes 5 for a fine edge on S30V.

I'd sure welcome other inputs here. In one respect it's kind of amazing that we're even here discussing the relative edge holding merits of a stainless with what was the acknowledged champion of edge holding just a few years ago.

Jerry,

I temper each one to 60Rc with all else being the same (at least as close as I can keep them). (Note: I sharpen both with a slack belt.)

I started noticing that even though S30V holds a fine edge for a long time, it seems that once it starts to lose that edge that it goes dull more quickly. IMHO: The D2 doesn't hold a fine edge as long but seems to stay usably sharp for a longer time. I have assumed this to be due to the larger size of the carbide particles in D2 but would like to hear from those of you who are much better metalurgists than I.

Gary

There was a time a few years back that I would say that if I could only have one blade steel to use I would be as happy with D2 as anything. (After I started forging I felt differently,) but as far as high (relatively) chromium content steel is concerned I still think D-2 is as tough and edge-durable as any 'stainless' that I had been using.

Recognizing that technically D-2 isn't a stainless per se, it performs as well if not better than ATS, in certain applications and I always thought it took a pretty good edge, and held it VERY well. I've got a heavy D-2 camp/chopper that is 6 years old. I've done alot of work with it and have only honed it with a ceramic and its alway shaving sharp. S30V IMHO sets a new standard though in stainless.

I can't address the carbide formations and their direct...or indirect effect on their respective cutting abilities. They are obviously considerably different. Without doing a 1 to 1 cutting comparison on the same mediums over time its not possible for me to say with any real confidence. But I think the 30 V seems to take a keener edge and hold that keen egde a long time....especially if its maintained. (honed) The D-2 may...as I think about it... like to keep cutting with less maintenence overall. However, I must say that I've not worked much D-2 in the last two years...since I've been doing other stuff. So I'm sure that my blade bevel and edge setting techniques have evolved and are different to a degree, than those I've applied to 30V lately.


Bottom Line:
I think that the key variable to control in a comparison like this is like always, blade grind and edge geometry, and their respective contribution to edge keeness and durability.

Honestly, I never thought of comparing 30V with D-2. Its a good question. But considering the price point for D-2 its still great stuff for blades and I hope it retains its popularity. .........:rolleyes: love that 30V!.........:D

Rob

This thread is troubling me a little, because I've not heard anyone who's been disappointed with S30V edge-holding. Gary, did you use quench plates with the S30V? It simply will not achieve full hardness without a very fast quench. What you're describing sounds a lot like a soft blade. The 4% Vanadium Carbides in S30V should provide a lot of wear resistance. The finer carbides achieved with the powder metallurgy should also wear better than the larger carbides in D2. That's one of the reasons D2 loses a fine edge faster; the bigger carbides simply fall out of the matrix. Finer carbides remain embedded longer. Something's wrong.

Unfortunately I've just sent a whole bunch of S30V blades off for hardening so I won't be doing more soon, but if you want to send me a small blade for testing, I'll put it in the next lot I send Paul - probably 3 months from now.

I use both of these steels and am very fond of each. S30V at 59-60 will get a finer sharp edge than D2 at 60-61. I try to not let my knives get dull, but my impression is that the S30V holds the edge slightly longer than D2, assuming no abuse.

The test I use for the superfine edge is to hold up a piece of toilet paper and slice down with the knife. D2 will almost always catch and tear the paper while S30V will slice it way down.

Steve, you might want to try some CPM-3V if you haven't yet. Hardened to Rc61/62, it will take an amazing edge.

Jerry,

Don't get me wrong, I'm not dissappointed in S30V's ability to hold a fine edge. It holds that fine edge for a long time. It's just that it seems that once it finally starts to lose that edge that it losses it quickly. I'm basing a lot of this on the folder that I've had in my pocket for the last year and use daily. I certainly can't complain about it's service since I've only resharpened it 5 times over that years service.

I'll be glad to send you a blade for Paul to H/T. I'd love to see how much different it turns out from the ones that I do. Let me know a couple of weeks before you're ready to send some off and I'll get a test blade to you.

To answer your question, yes I have gone to using quench plates since Ed Severson suggested it to me last winter. I don't own a rockwell tester but by checking with files, I am getting hard enough that they won't touch the blades.

I'm certainly no metalurgist, but I haven't heard of D2 losing carbides from the matrix steel. What are you basing this on? I have always credited it's edge holding to the carbides.

Gary

Gary, I was basing that on what had long been said of stainless and large chromium carbides. D2 has a lot of those same carbides as well as a coarse grain structure. Maybe it's just hearsay. I'm certainly not suggesting that D2 has similar wear qualities to most stainless', but it has similar structure qualities. With 1.5% carbon it sure has lots of carbides though.

I'll never remember to email you when I send more blades to Paul. Just send one in about three months, and I should be about ready then.

Jerry,

I have thought about 3V, but the specs on Crucible's site suggest that you need to harden at 2050F to get a tempered hardness over 59 HRC. My little furnace strains to reach 2000F, so I haven't tried it.

Your posts indicate that 1950F will work and I will try it out soon. I am looking for some aluminum plates at present to use with my S30V. I have gotten decent results with oil as suggested on Crucible's site, but have been convinced to go with the quench plates.

I periodically get blades tested at a machine shop for Hardness. I test the rest with a nickolson file, assuming it to run ~60 HRC.

Steve,

I just checked my notes. Paul uses 1975F to harden and 950Fto temper. His process, which includes cryo after a snap temper, gets Rc61, but I've gotten a couple recent batches at Rc62.

I spent some time this past weekend with a knifemaker who has had problems with S30V edges. What I observed from one of this knives was that the edge was fairly coarse. He uses 220 grit for sharpening. I have always taken my edges down to 16 micron, Norax X16, and on very fine edges will go to X5's. I think this makes a big difference in edge strength and durability. Many people like a toothy edge, but it's been my experience they don't last long; the teeth on the microserrations break off and it goes dull very suddenly.