3V questions.

[jdm61]

I just ordered a chunk of .210 thick 3V from Aldo to make a couple of prototypes. Yes, I am making a couple of stock removal knives, heaven forgive me. I am not going to even attempt to heat treat this stuff, so i will be sending it off to someone like Peters. My question is this. Peters says to not grind an edge down to less than .015 or you run the risk of having the edge warp all wavy. How thin do you guys grind this stuff before HT? I want to do as little girding as possible after HT because I suspect that this stuff is pretty freaking abrasion resistant with all of that vanadium, etc. in it after it is hardened. With that said, .015 is about where i would take a blade made from such an impact resistant steel to before I put the final edge on it. I might even leave it .020. .015 seems might thin. Also, what does the surface look like coming back from heat treat when they are using the vacuum oven and pressurized gas quench? who close can you take a blade to final finish? I'm looking to have the stuff hardened in the 60-61Rc range.

 

[butcher_block]

3v is much tougher then many other "plain " steels and yes if your not used to grinding higher alloy blends then yes its hard on belts but if you have ground cpm154 its not any harder

i got to call aldo and get some more 3v for my camp knife

 

[Justin King]

I usually grind larger 3v blades to .018-.020 before sending to Peter's, smaller blades I go right to .015" and I finish to 320 or 400 beforehand also. It comes back with a thin layer of purple-colored oxides, which sands off easily. I have experienced the wavy edge from grinding them too thin also, don't go under .015.

 

[jdm61]

Thanks, Justin. So you can go right to cleanup,final polish and sharpening right back from heat treatment? What do you consider larger and smaller blades? Do you take your standard 4+ inch field knife down to .015?

I usually grind larger 3v blades to .018-.020 before sending to Peter's, smaller blades I go right to .015" and I finish to 320 or 400 beforehand also. It comes back with a thin layer of purple-colored oxides, which sands off easily. I have experienced the wavy edge from grinding them too thin also, don't go under .015.

 

[jdm61]

3v is much tougher then many other "plain " steels and yes if your not used to grinding higher alloy blends then yes its hard on belts but if you have ground cpm154 its not any harder

i got to call aldo and get some more 3v for my camp knife

Butch, the highest alloy steel that I have worked with is CruForge, which isn't very high alloy compared to some of the other stuff. i am less worried about belt usage and more about finishing.

 

[Justin King]

Thanks, Justin. So you can go right to cleanup,final polish and sharpening right back from heat treatment? What do you consider larger and smaller blades? Do you take your standard 4+ inch field knife down to .015?

Yes, remove the oxides and your blades have the same surface condition that you send them out with.
Under 5" blade is small to my way of thinking (not big enough for heavy chopping). Most blades over 6" in length I assume will be used to chop with, .018-.020 is what I usually grind these to. 3v is worth playing with a bit to see just how thin you can comfortably take the edge for your purposes, it is tough and hard enough to support a thinner edge than I would use, if I were making the same blades from another steel.
If you have been getting your Cru-Forge to full hardness then the 3v will give you a familiar feel when working it post-HT. Vanadium carbides...

 

[james terrio]

Yes, I am making a couple of stock removal knives, heaven forgive me.

Welcome to the Dark Side. You're going to love it here! (cue evil laughter)

I completely agree with Justin and Butch on all their points. Especially, unless the stock is really thin*, completely finish the the blade before having Peters' HT it, except for actual sharpening. You do NOT want to be hand-sanding 220-grit scratches out of hardened 3V!!

To me, the entire point of using 3V for knives is that it's very tough and can support a thinner-than-"normal" edge without chipping. It also happens to be very wear-resistant. I've only made a few with it so far, so further testing on my part is required, but I already like this steel a whole lot.

I've had several recent discussions with folks who have a lot of experience with 3V and all the other great, favorite cutlery alloys, both on the forums and on the phone. To a man, they recommended to go ahead and ask for 62Rc on small/medium slicers to maximize edge-holding, and tone it down to 58-59Rc for choppers to maximize toughness.

*I just got in a test piece of 3V at .048" , which I will clean up, drill and profile pre-HT. It will be beveled post-HT (to avoid warping) and I'm telling you right now it's going to have a belt finish, not a hand-polish

 

[jdm61]

James, my initial prototypes will be a 5.5 inch drop point field knife and a 6.5 inch clip point fighter, so I am thinking about that 60-61RC range. Does that sound like a good plan? From what I have read and been told, I am not sure that I would want to go to 62 on those unless I was able to find a place using salt baths and the lower tempering temps combined with multiple cryo steps. The Crucible factory specs seem to indicate that 60RC gives you a really good combination of toughness and wear resistance. If a chopper ends up happening, it will be after I do a smaller field knife in the 4-4.5 inch range.

Welcome to the Dark Side. You're going to love it here! (cue evil laughter)

I completely agree with Justin and Butch on all their points. Especially, unless the stock is really thin*, completely finish the the blade before having Peters' HT it, except for actual sharpening. You do NOT want to be hand-sanding 220-grit scratches out of hardened 3V!!

To me, the entire point of using 3V for knives is that it's very tough and can support a thinner-than-"normal" edge without chipping. It also happens to be very wear-resistant. I've only made a few with it so far, so further testing on my part is required, but I already like this steel a whole lot.

I've had several recent discussions with folks who have a lot of experience with 3V and all the other great, favorite cutlery alloys, both on the forums and on the phone. To a man, they recommended to go ahead and ask for 62Rc on small/medium slicers to maximize edge-holding, and tone it down to 58-59Rc for choppers to maximize toughness.

*I just got in a test piece of 3V at .048" , which I will clean up, drill and profile pre-HT. It will be beveled post-HT (to avoid warping) and I'm telling you right now it's going to have a belt finish, not a hand-polish

 

[james terrio]

Does that sound like a good plan?

In a word, yes. I think we're in a similar place in experimenting with 3V with these geometries and HT protocols, and I look forward to your results. I will take a semi-educated guess that specific quenching, tempering and cryo techniques could squeeze the very most potential out of this alloy, but I have no solid data on that.

The upshot is, my personal experience with my own 4-5" blades in 3V at 59Rc, as HT'ed by Peters', with thin (.015-.020") edges are the toughest, most wear-resistant blades I've tried so far. (noticeably better in those regards than O1, 1084, CPM-154, D2 and 440C [the last two are no longer relevant to me in any case, due to terrible QC]; CTS-XHP comes the closest but it's becoming steadily more difficult to get, and QC problems have been raising an ugly head lately according to my sources... ElMax shows a great deal of promise to take the place of, or surpass CTS-XHP, but I haven't tested it in use yet, and I doubt very strongly that it will equal 3V in toughness).

 

[jdm61]

I may be wrong on this, but I have heard that Elmax requires a pretty crazy heat treat, at least as far as how hot you have to get it and with stuff like 3V, 4V, S35VN and CTS-XHP, crazy HT appears to be optional. I would like at some point to be able to do my own insanely complicated HT on stuff like 3V, but i suspect that I have about $7-8k for a full 3 pot salt system and a big mofo cryo dewar standing between me and that, not to mention a bombproof bunker of a new shop with 50 amp power. A power hammer and surface grinder are probably higher up the wish list at this point.

In a word, yes. I think we're in a similar place in experimenting with 3V with these geometries and HT protocols, and I look forward to your results. I will take a semi-educated guess that specific quenching, tempering and cryo techniques could squeeze the very most potential out of this alloy, but I have no solid data on that.

The upshot is, my personal experience with my own 4-5" blades in 3V at 59Rc, as HT'ed by Peters', with thin (.015-.020") edges are the toughest, most wear-resistant blades I've tried so far. (noticeably better in those regards than O1, 1084, CPM-154, D2 and 440C [the last two are no longer relevant to me in any case, due to terrible QC]; CTS-XHP comes the closest but it's becoming steadily more difficult to get, and QC problems have been raising an ugly head lately according to my sources... ElMax shows a great deal of promise to take the place of, or surpass CTS-XHP, but I haven't tested it in use yet, and I doubt very strongly that it will equal 3V in toughness).

 

[james terrio]

I may be wrong on this, but I have heard that Elmax requires a pretty crazy heat treat...

"Crazy" HT is not "optional" with ElMax, 3V, M4, etc. etc... it's necessary; otherwise one may as well torch up some old leaf-springs and dunk it in rancid bacon-grease and save a boatload of money. High-alloy steel is just like that. As it happens, I happen to know the guy who developed the published protocol for ElMax in cutlery applications. I would certainly not attempt it in my own shop. Hint-hint wink-wink nudge-nudge.

 

[jdm61]

LOL. What I meant was that i looked at the published specs for Elmax and the "required" austenizing temperature would weld together most of the steels that I have used so far!!!! I know that my 24 inch Paragon will, in theory, get up to the 1950-1975 or so that you can use for 3V, but it may not be able to get hot enough for Elmax, at least not without blowing every breaker in my complex.

"Crazy" HT is not "optional" with ElMax, 3V, M4, etc. etc... it's necessary; otherwise one may as well torch up some old leaf-springs and dunk it in rancid bacon-grease and save a boatload of money. High-alloy steel is just like that. As it happens, I happen to know the guy who developed the published protocol for ElMax in cutlery applications. I would certainly not attempt it in my own shop. Hint-hint wink-wink nudge-nudge.

 

[Phil705]

So back to edge thickness before HT. Where exactly do you suggest determining edge thickness? Precisely at the edge? 1/8" from the edge? Where?

Thanks

 

[james terrio]

As close to the edge as possible. Meaning the actual, um, edge.

 

[jdm61]

I got my Aldo car package today. The 3V looks nice. Very little "bark" and nice and straight. I did a little cutting on the bandsaw and it wasn't too bad, but it is probably 80% or less of the thickness of the CruForgeV that I had been cutting so that makes a difference. With that said, I can definitely understand the advantage of water jet cutting if you want to profile more than a couple of blades at a time.