Sharpening, which grit for which knife?

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crn3371

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Nov 1, 2019
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Is there a guide out there that has general suggestions for the various angles and edges one can put on a knife? What is a toothy edge, and why do you want it? When is a mirror edge appropriate? Edge on a kitchen knife vs that for an edc? I’m guessing that there’s no hard rules, but there must be a rule of thumb. For example, I just got a new Buck 119 and was a bit surprised that the edge wasn’t what I would consider as sharp. It was a pretty coarse edge and barely cut paper, yet I’m guessing that it was deliberately done that way by Buck. I just got a Hapstone R2 and have the ability to go down to 0.1 micron lapping film, but I doubt that I want to take every edge to that level. Help point me in the right direction.
 
Toothy edges are formed by coarse grit, with a pattern of grooves formed by the grit that can be thought of like micro-serrations (although they aren't, technically) and are best for slicing cuts, but worse for push-cutting. Polished edges are best for pushing cuts but quickly blunt compared to toothy edges when used for slicing work. Usually a balance between the two qualities is what you're after, and that will depend on your applications for the tool.
 
I’m generally happy in the 600-1000 grit range with a 6 micron strop.
YMMV
 
The most important thing imo is that the bur is removed. A 140 grit edge deburred will cut arm hair. Most of my.needs are in the kitchen and on my edc. and a folding dmt 220/600 meets my needs. With the exception of the santoku which I refine to 1200 for chopping. My edc gets the 220/600 and works great for what I need. I do occasionally refine to my Shapton 30k. But 325 edge cuts great and is very practical. Whittling hair isn't practical unless you have a reason to. Try everything and see what you like. Don't get mad at yourself if you find a coarse edge delivers what you need.
 
This is the kind of input I’m after. I see the all sharpening videos where they’re cutting cigarette paper, and while impressive, I’m not sure how practical the actual edge is. So, achieving the lowest Bess score doesn’t necessarily translate to the best edge?
 
If your push cutting then a 1200 will do unless your cutting sushi which I don't. If your slicing 325 to 600 works great. And the edge will hold longer. The "sharper" anything gets the thinner it becomes. Slap that teeny tiny edge on a cutting board and it will fold over quickly.
 
I'm also in the camp that usually stops around 600 grit. It's plenty sharp for most cutting. I may go to 1000 for some of my kitchen knives depending on what I'm cutting.
 
All depends what you do

I'm mostly happy with a 400 grit venev finish followed by a 6 micron diamond grit strop

But I will go 800 at times
 
For EDC folder and kitchen knife, I'd use 1000 grit and a green strop

For impressing people on Youtube and Instagram, I'd use 4000 grit stone then strop to 0.3 micron (don't have the 0.1 or 0.025 micron yet)
 
crn3371 said:
Is there a guide out there that has general suggestions for the various angles and edges one can put on a knife? What is a toothy edge, and why do you want it? When is a mirror edge appropriate? Edge on a kitchen knife vs that for an edc? I’m guessing that there’s no hard rules, but there must be a rule of thumb. For example, I just got a new Buck 119 and was a bit surprised that the edge wasn’t what I would consider as sharp. It was a pretty coarse edge and barely cut paper, yet I’m guessing that it was deliberately done that way by Buck. I just got a Hapstone R2 and have the ability to go down to 0.1 micron lapping film, but I doubt that I want to take every edge to that level. Help point me in the right direction.
Click to expand...
It depends on the type of knife and what I want the knife to do. For a general purpose kitchen knife, I generally use a 1200 grit DMT. This also goes for a boning or carving knife in the kitchen. For a fishing or hunting knife, I want a finer edge for dealing with fish, for example. I go to a fine Spyderco ceramic after the medium for a pocket knife in VG10.
Woodworking tools are a different story, but a similar principle applies. If honing a chisel for chopping, I use a less acute edge angle and I still want a fine edge. For a paring chisel, I go past a black hard or translucent Arkansas stone and finish with 1 micron Norton diamond paste on a hard leather strop. The same holds for plane irons.
 
As others have said, there's little practical value in going past 1000 grit. That said, I like a mirrorish edge on my EDC knives and don't carry anything that hasn't been stropped down to at least .5 micron.
 
crn3371 said:
Is there a guide out there that has general suggestions for the various angles and edges one can put on a knife? What is a toothy edge, and why do you want it? When is a mirror edge appropriate? Edge on a kitchen knife vs that for an edc? I’m guessing that there’s no hard rules, but there must be a rule of thumb. For example, I just got a new Buck 119 and was a bit surprised that the edge wasn’t what I would consider as sharp. It was a pretty coarse edge and barely cut paper, yet I’m guessing that it was deliberately done that way by Buck. I just got a Hapstone R2 and have the ability to go down to 0.1 micron lapping film, but I doubt that I want to take every edge to that level. Help point me in the right direction.
Click to expand...
I assume your Buck 119 will be primarily used as a general purpose every day knife, doing slicing primarily? If so, keep the final edge finish on a low-ish grit for a nice toothy edge. The factory edge is bound to be inconsistent and of a low quality, so make sure to re-profile it with the angle of your choice - likely around 20 degrees per side or less, even possibly as low as 15 dps if you're happy to put in some elbow grease to set a new angle.

For final finish, don't concentrate too much on a specific grit recommendation, because it will vary wildly depending on what grit rating is used by your stone brand. As an example, if you got yourself a set of Venev stones with the Hapstone R2, then finishing at 400 grit, or even 240 grit would be plenty good enough. If you have the generic diamond plated Chinese stones with your R2, then you could finish around 800-ish grit for a similar edge.
 
Grit ratings are for sure complicated. Gritomatic has provided a great resource comparing their relative values: https://www.gritomatic.com/pages/grit-chart

I believe most whet stone manufacturers use the FEPA-P scale. Venev uses the F scale, where a 400 grit is equivalent to about an 825 grit on the P scale, according to the chart. I believe that's accurate, looking at the scratch pattern of my Venev 400 compared to a Shapton Glass 1000.
 
Every country has a different grit rating, the only reason I can think of is to confuse the end user. When talking about grit, I assume that people are using the Japanese JIS standard because they almost always put the grit rating on the stone so it’s much more recognizable, while US made stones likes Spyderco or DMT just say ‘fine’ ‘medium’ ‘extra fine’ and then I’ll have to look online to see what ANSI or Mesh grit is it.

So if you want to be absolutely accurate, use micron
 
There's a decent variation even within makers who use the same rating system, e.g., a Shapton Pro 1000 is closer to a Chosera 800 than it is to the Chosera 1000.
 
000Robert said:
I found this Sharpening Abrasives Chart but I'm not sure how accurate that it is.

View attachment 1686134
Click to expand...

That chart is very precise, it's on Gritomatic website, they are the retailer of the TSPROF sharpening system

www.gritomatic.com

Grit Chart

A logarithmic scale has the property of equidistant spacing for any geometric progression, meaning that a ideal stone series will be uniformly spaced.
www.gritomatic.com www.gritomatic.com
 
PMQ said:
That chart is very precise, it's on Gritomatic website, they are the retailer of the TSPROF sharpening system

www.gritomatic.com

Grit Chart

A logarithmic scale has the property of equidistant spacing for any geometric progression, meaning that a ideal stone series will be uniformly spaced.
www.gritomatic.com www.gritomatic.com
Click to expand...

The chart even looks prettier on their website. I don't remember where I got it at.
 
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