Sal: How best to sharpen the ZDP Delica 4

[rs2]

Hello Sal! I have had my ZDP D4 for a couple weeks, and just want to thank you - it is outstanding!

In the event it should someday need to be touched up on my Sharpmaker (it doesn't yet), what angles do you recommend for it? I use 30 degrees on all my other Spydercos.

Thank you sir!

[Ted]

IIRC all Spyderco factory edges are 30 degr. That way, you can easily touch them up with 40 degr. Once that doesn't go as easy anymore, you can redo the 'back' or 'secondary' bevel on 30 degr. If you were to sharpen on 30 degr every time, you are removing a lot of metal every time. That combined with the hard ZDP-189 you're in for some hard work

[ghostrider]

[quote="Ted"]IIRC all Spyderco factory edges are 30 degr. That way, you can easily touch them up with 40 degr. Once that doesn't go as easy anymore, you can redo the 'back' or 'secondary' bevel on 30 degr. If you were to sharpen on 30 degr every time, you are removing a lot of metal every time. That combined with the hard ZDP-189 you're in for some hard work ]
Would that apply to the ZDP-189?

I thought people were saying that the Caly Jr. ZDP-189's were sharpened at something like 12 or 15 degrees inclusive because the steel could handle the accute angle. :confused:

Now I also would like to hear the answer to this one.

[eljay]

They sure seem to be at something less than 30 degrees. As far as I can tell with either the ZDP Caly Jr or the D4 if you sharpen at 30 degrees it's just hitting the edge, not higher up. I've always assumed this is part of why it cuts so well - it's not that ZDP's magic, it's that it can hold such a narrow angle with reasonable edge retention.

I've found that just a quick touchup with a few strokes with the flat of the white stones will do a surprising amount with the ZDP knives, and just occasionally do I go all the way back to the brown stones and go through the whole 20x4 ritual.

[Ted]

They sure seem to be at something less than 30 degrees. As far as I can tell with either the ZDP Caly Jr or the D4 if you sharpen at 30 degrees it's just hitting the edge, not higher up. I've always assumed this is part of why it cuts so well - it's not that ZDP's magic, it's that it can hold such a narrow angle with reasonable edge retention.

I've found that just a quick touchup with a few strokes with the flat of the white stones will do a surprising amount with the ZDP knives, and just occasionally do I go all the way back to the brown stones and go through the whole 20x4 ritual.

eljay, keep in mind that the 20x4 ritual is just a rule of thumb. If you have not 'raised a burr' after 20 on each side, you'll need to continue before switching sides & stones.

[Ed Schempp]

ZDP is 3% Carbon 20% Chrome. Chrome carbides run about RC 68 giving the steel a hardness of about RC67. This material while hard is not that difficult to sharpen compared to S30V with RC 84 Vanadium carbides...Take Care...Ed

[eljay]

eljay, keep in mind that the 20x4 ritual is just a rule of thumb. If you have not 'raised a burr' after 20 on each side, you'll need to continue before switching sides & stones.

Yes, yes yes, but as a shorthand I think it conveys the point.

[Tim8557]

Would that apply to the ZDP-189?

I thought people were saying that the Caly Jr. ZDP-189's were sharpened at something like 12 or 15 degrees inclusive because the steel could handle the accute angle. :confused:

Now I also would like to hear the answer to this one.

I believe that the Caly was around 12 degrees PER side; 24 degrees inclusive.

I reprofiled mine on the Edge Pro to 10 degrees per side and then a cutting edge at 12 degrees. The one thing I recall was that you do not raise a big burr. It's very subtle.

[The Mastiff]

ZDP is 3% Carbon 20% Chrome. Chrome carbides run about RC 68 giving the steel a hardness of about RC67. This material while hard is not that difficult to sharpen compared to S30V with RC 84 Vanadium carbides...Take Care...Ed

Ed, according to the chart Vassali posted it has some molybendum and tungsten in it, though the amounts aren't given. We really don't know what's in that stuff right now. I think we know it's a bit brittle in some circumstances, but not as simple a steel as just carbon and chrome plain stainless. Wouldn't that be almost unusable without cladding if it was? My delica is holding up fine, though I da__ sure not torturing it. Thanks. Joe L.

[Ed Schempp]

I believe that the moly and tungston are at fairly low levels and used mainly for grain refinement. I don't think they were significant in the early spectral burns. If they contibuted to the carbide volume they would have to be a higher levels than detected by the burn. I'm speculating here but I doubt that they are little more than a very small percentage of the carbide volume.

I sharpen with a belt grinder and have not noticed any difficultly sharpening ZDP. M4 is fairly high in carbide volume, Tungston, Molybium and Vanadium carbides at like a 12% volume. It is much harder to sharpen than ZDP. Yes ZDP it is brittle compared to many knife steels; but it does cut very well...Take Care...Ed

[The Mastiff]

I believe that the moly and tungston are at fairly low levels and used mainly for grain refinement. I don't think they were significant in the early spectral burns.

I wasn't aware an analysis was done. Thanks for the info. Tungsten carbides wouldn't be as hard as vanadium in any event from what I've read.

M2 was my favorite steel since Benchmade came out with theirs ( I have 2). I have been waiting a year or two to try an M4 knife. I've been "suggesting" (re: asking without grovelling too much) Sal to do something in S125 and M4 eventually. I love being involved with these sprint run experiments.


Aren't you doing a few knives for Spyderco? 3V hunters and a folder IIRC? Thanks, Joe L./Raleigh

[The Mastiff]

Double post. My regrets. JL

[rs2]

Thanks gentlemen. I appreciate all the information. I've learned things about ZDP I didn't even know I didn't know. :o

But, I'm still not sure what the definitive answer is on the proper sharpening angle. :confused:

[sal]

Hi RS2,

I use 30 degrees.

sal

[Cameron23]

I've been using the 30 Degree setting for the ZDP D4. The 40 Degree took away its ability to whittle hair.

It's been working better since sticking with the 30. :)

C :spyder:

PS...Thank You Sal. I'm lovin' everything about it.

[rs2]

Hi RS2,

I use 30 degrees.

sal

Thank you, Sal. That's what I'll use then, IF this blade ever dulls. :)

[skcusloa]

I've already sharpened my zdp delica. At 30 degrees it is only hitting the edge.

In my experience so far, zdp stays sharp for a long time, but it doesn't hold a razor edge much longer than other high end steels I've used.

[papadb10]

This was posted by Cliff Stamp in a review of the Blue delica zdp.

The forth generation Spyderco Delica in ZDP-189 has the same design as the VG-10 version, full specifications can be seen in its review of the forth generation VG-10 plain edge Spyderco Delica.The only significant difference, aside from the steel, is that the edge geometry is different, specifically this one is ground from 0.022-0.025" at the edge and sharpened at 12.7 (2) degrees per side.

[papadb10]

Sorry, I forgot to add the link to the review. Here it is.

http://www.physics.mun.ca/~sstamp/knive ... p_189.html

[Native Justice]

On my new D-4, I'd have to agree with Skus but it does strop very nicely to a scary edge with aluminum oxide on leather or cardboard easily, as does S30V after reprofiling. Time will tell as I haven't played with sharpening it yet but this is usually a good sign. :D