# The Grind



## Dave Martell (Jun 29, 2017)

Lots of folks ask me what my grind is like, or (based on pictures) they assume that I grind flat sided blades. Every once in awhile I post a picture to illustrate just how they are actually ground. 

A thin bottom half for ease of cut and a mid point bulge for release is what I aim for. I also taper the spine, but ONLY enough to keep it out of the way of the cut because I hate thin bendy spined knives so I don't make those.

I know that food release on my knives is decent. My own testing and feedback from so many customers and users has proven this to me. Is it the be all end all of food release? No of course not. Grinding knives is a balancing act, finding the sweet spot is the goal and the goal line is always moving.  

So anyway, here's the grind on my knives....
_*Note - this is just an initial rough grind to show clearly how my knives are worked. This is not the actual final finish. _


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## ThEoRy (Jun 29, 2017)

I think that illustrates it perfectly.


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## daddy yo yo (Jun 29, 2017)

Dave, this as well as that could be interesting for someone who is on your list... :whistling::whistling::whistling:


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## Dave Martell (Jun 29, 2017)

ThEoRy said:


> I think that illustrates it perfectly.




Thanks for chiming in Rick. You might not know this but I learned a lot about this stuff from you over the years. I listened when you talked and especially when I had to re-work your gyuto I didn't do so well on back when I started. I always think about you when I'm grinding the front part of the blade, and yeah that's the truth right there!.


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## Dave Martell (Jun 29, 2017)

daddy yo yo said:


> Dave, this as well as that could be interesting for someone who is on your list... :whistling::whistling::whistling:




VERY wise post Manuel!


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## Nemo (Jun 29, 2017)

Thanks for illustrating this Dave.

Just so I'm sure I have it right: Do your knives have a kind of hidden shinogi? Do you convex the blade road? Is there a lot of right hand bias to the blade road grind?

How is the edge ground? Is it a continuation of the blade road grind (perhaps with a microbevel) or is there a primary bevel? Is the edge centred in relation to the spine (this is what I take to be a 50-50 grind, please educate me if I have this wrong).

Assuming I want to follow the original grind (I do), at what approximate angle should the edge be stropped or sharpened? Is it the same on each side?

As always, please don't feel compelled to disclose any trade secrets


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## malexthekid (Jun 29, 2017)

He grinds 50-50 as close to humanly possible for hand ground... can't really answer the rest as I only have a petty from him (so far). 

And I would suggest the edge is reasonably obtuse given the size of bevel on my petty (i am assuming you sharpen all knives relatively consistently)
I will say and blade from Dave is likely to be in the running, if not be, the sharpest knife ootb you have, and will ever, experience


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## foody518 (Jun 29, 2017)

Dave, thanks for sharing this explanation of your grind


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## Dave Martell (Jun 29, 2017)

malexthekid said:


> He grinds 50-50 as close to humanly possible for hand ground... can't really answer the rest as I only have a petty from him (so far).
> 
> And I would suggest the edge is reasonably obtuse given the size of bevel on my petty (i am assuming you sharpen all knives relatively consistently)
> I will say and blade from Dave is likely to be in the running, if not be, the sharpest knife ootb you have, and will ever, experience




Thanks for jumping in Alex.


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## Dave Martell (Jun 29, 2017)

Nemo said:


> Just so I'm sure I have it right: Do your knives have a kind of hidden shinogi? Do you convex the blade road?




They start out with a shinogi line but I round it over during finishing. I tested both ways (crisp shinogi vs rounded over) and the clear winner was the rounded version because the crisp shinogi wedged a lot more. I doubt that this is true for all knives, and know it's not true for single bevels, but for my grind this is the case.






Nemo said:


> Is there a lot of right hand bias to the blade road grind?




None at all. My knives are ground as symmetrical as humanly possible. 







Nemo said:


> How is the edge ground? Is it a continuation of the blade road grind (perhaps with a microbevel) or is there a primary bevel? Is the edge centred in relation to the spine (this is what I take to be a 50-50 grind, please educate me if I have this wrong).




I grind the edge only when the two sides of the knife are about to meet. At this point I use a diamond stone to join the two sides. This is tricky business doing it this way (post grind vs pre-grind) but I like what it shows me. By creating the edge post grind I am given a look at how even my grind is along the length of both sides. I can then do additional grinding (tweaks) to the blade grind to make it even along it's length and matching on both sides. I started doing it this way because of the familiarization in doing this during blade thinning on so many Japanese knives over the years. Basically what I'm saying here is that I use the edge height as a guide to show me blade/edge thickness so that I can adjust.

Yes the edge is centered as much as humanly possible to the center of the spine. 

Yes my knives are 50/50 ground - both the blade and the edges. Right or left handedness is not an issue here.








Nemo said:


> Assuming I want to follow the original grind (I do), at what approximate angle should the edge be stropped or sharpened? Is it the same on each side?




The edge bevel has been created on my knives to be at the same angle on each side. Since I freehand sharpen I can't tell you what angle the edge has been created at. But that doesn't matter anyway, angles have little meaning to us, they're just numbers. What is important is to sharpen/hone/strop/thin/repair at what angle the knife/edge needs and how to find this information out. See *THIS post* for some help.


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## Nemo (Jun 29, 2017)

Thanks for that info Dave, it really helps me understand your grind but also the reasoning behind it, which also adds to my understanding of knife geometry in general.

And thinking back to the "real deal" thread, I realise that I should have known that the answer to the last Qn was in essence "follow the geometry that the maker has provided for you".


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## Dave Martell (Jun 29, 2017)

Nemo said:


> Thanks for that info Dave, it really helps me understand your grind but also the reasoning behind it, which also adds to my understanding of knife geometry in general.
> 
> And thinking back to the "real deal" thread, I realise that I should have known that the answer to the last Qn was in essence "follow the geometry that the maker has provided for you".




There's always others who are thinking the same things but don't ask. I have no problem answering questions like this.


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## aboynamedsuita (Jun 29, 2017)

That grind is nice and high up, I think there were also a couple older threads that also had some pictures?


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## Dave Martell (Jun 30, 2017)

aboynamedsuita said:


> That grind is nice and high up, I think there were also a couple older threads that also had some pictures?




Yeah I've posted on this before....somewhere.


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