Sharpening Progression 101: Rules of Thumb

Rules of thumb
1) Minimizing the stones in your progression minimizes accumulated mistakes. Stick to 2-4 max.
2) Grit jumps should roughly double. Higher grits can be bigger jumps.
Example 400grit, 800grit, 3000grit, 1um strop.

[@rubencarvalho230]

This was very helpful. Thank you so much for this video.

[@EngineersPerspective701]

Awesome, glad it helped!

[@adanma17]

One tip that has helped me greatly was to always get a good low grit stone to create the apex ,makes polishing so much easier.

[@EngineersPerspective701]

Agreed, the first stone is the progression is THE most important!

[@eee2115]

Do you have to create a burr and remove it on each of the stones in your progression or is the second stone more of a polish, rather than a burr creation? So, create burr with 600 grit, a few light passes to remove the burr. Go to 1000 grit, create burr/remove burr, then go to strop? Or do you just polish/light passes on the 1000 grit without creating a burr? I just got the Atoma 1200 after returning my DMT which came in with obvious imperfections and unevenness in the sharpening surface. What a difference in quality!

[@EngineersPerspective701]

Assuming you're doing a 3 stone progression here. You must form a burr on both sides with your lowest grit. You can reduce it on that same grit but it likely would be better to just move on to your medium grit if you're a beginner. Flip the burr to the opposite with the medium grit but now, do not try to make it any larger than you have to. Flip the burr to the opposite side again so that both sides were apexed on the medium grit. Likely the burr is now smaller than before but if it is still quite large then use alternating light passes to reduce the burr to set yourself up for the last stone. Flip the burr to both sides again on the final stone but really pay attention to keeping the burr as minimal as possible while still confirming you have apexed the edge. Now reduce/eliminate the burr on the highest grit and go to strop once the edge is relatively clean. Depending on the stones, steel and heat treat you will be able to get away with less work or maybe require more in places. Hope that helps!

[@eee2115]

Thanks for the explanation. I just got the Atoma 600, so have 2 stones now. May get something around 3k for my finish stone. @@EngineersPerspective701

[@scottc3165]

As a beginner, I was wondering how to know when you're done with one grit and ready to go to the next finer grit.

[@turing2376]

A sharpening video! Excellent, concise explanation. Cant wait for part 2. "Accumulated error" you mention I believe is one of the biggest problems I have had though I'm sure there may be others as well. 😅 The concept of grit rating of abrasive as related to width of edge apex formed interests me. I recently used coarse DMT -> 4 micron strop -> 1 micron strop and was hair whittling and shaving. Didnt have to spend very long stropping, probably just a few minutes total, maybe 30 passes total per strop. Could not detect any burr whatsoever, at least via touch, shining light on edge and using jewler's loupe. The knife was spyderco mbs-26 petty. Dont know hardness but maybe the combination of narrow bevel and easily abraidable steel meant that I was able to get away with such an easy jump in grit. I wonder...

[@EngineersPerspective701]

A fully deburred DMT coarse edge with a light strop is SICK! It cuts like how I imagine the traction in an AWD Lamborgini feels. I highly recommend checking out the Gritomatic universal grit chart to get a better understanding of grit ratings. I'm constantly referencing that to see how different stones compare! On science of sharp, it was noted that for DMT plates the edge apex for both the coarse and fine were roughly equivalent the extra fine. And the scratches were larger diameter but less deep than the extra fine. His hypotheses was it had to do with the how the pressure is distributed over the larger diamond particle. Because the force is distributed over a larger area the pressure on the diamond crystal decreases and the depth of the cut. There is also a "microbevel" effect than can occur and it's pretty hard to explain. I've experienced it significantly on the KME doing the 140grit to 300grit jump. Essentially the 300grit doesn't make contact with edge because the 140 "knocked" the apex over from both sides, creating a microbevel. So it's extremely important to properly apex after that jump. I haven't seen even close to as big an issue going form DMT coarse to DMT fine though. I've talked with Hap Stanley a bit and he mentioned from his testing with bound abrasives (not plates) that alumina cuts about 30% of the particle diameter whereas diamond is closer to 70%. For example a 100 micron diamond particle would cut 70 microns deep. That MBS steel is pretty nice and I think they shoot somewhere in the 60-62HRc range. I think your good results are due to good steel, heat treat and geometry along with SKILL and the above factors. I still haven't made a dedicated "How to Get an Aggressive Edge" video because I'm still experimenting a little before I do it!

[@turing2376]

@@EngineersPerspective701 Ahh, that is very interesting about the DMT extra fine making deeper scratches than coarse or fine. I wish I knew that before. I have the extra fine and extra extra fine plates and never use them because they left poor finnish despite finer grit rating. I tried to "wear" them in, not exactly knowing what I was doing, rubbing steel plate against them, but no difference. Now at least I dont feel like maybe it was just me. I will definitely have to check out this science of sharp channel. Look forward to part 2 and hopefully eventual discussion of getting an aggressive edge!

[@EngineersPerspective701]

@@turing2376 Science of Sharp is a website. It's 99% razor blade specific so the full translation to other blades isn't completely understood. Linked below. scienceofsharp.com/2015/03/01/the-diamond-plate-progression/ Do you watch big brown bear on YT? If you do what he does in his sharpening you'll get an aggressive edge. Here is a good one and also his maxamet sharpening videos are great too. I've rewatched these many times and I gain more knowledge each time as my sharpening skills increase. kzbin.info/www/bejne/pHnVeKZpnaitnck

[@turing2376]

@@EngineersPerspective701 Have watched BBB but will have to go back and watch those videos. Thanks.

[@turing2376]

@@EngineersPerspective701 read that science of sharp article. I always wondered how Michael Christy got those great edges off of those finer DMT stones after the terrible experience I had with them. May that was it, he got it nice and toothy on those finer DMTs then polished the hell out of those teeth with all that stropping!!! Hahaha...then again there might be a little more to it 🤣

[@_BLANK_BLANK]

I feel like time on the stones is more important to keep in mind, than number of stones. I regularly use a 4 to 5 stone progression (sharpening professionally) but I dont spend very long on each stone.

[@EngineersPerspective701]

Agree and disagree! Keep in mind I’m not saying good results can’t be had though! It’s just a recommendation for new sharpeners! Agreed that minimizing the total number of strokes is key to reducing accumulated error. My issue with more than 3 stones is 1) Often but not always it doesn’t make a huge difference in results to decrease the size of the grit jumps by going higher than 3 unless you’re shooting for a mirror. 2) I suggest deburring completely between grit jumps and this really increases the total stroke count if you add extra stones. Of course you could just forgo that altogether. 3) Having to stop and readjust isn’t ideal for perfect consistency.

[@_BLANK_BLANK]

@@EngineersPerspective701 usually I do go for a mirror polish (if it makes sense for the customers steel) so it's a quick progression of 60 grit (bryxco manticore) to 300 to 1000 to 8000 to strops most of the time.

[@EngineersPerspective701]

@@_BLANK_BLANK a quality mirror can be pretty unforgiving of big grit jumps especially on same steels that don’t take a polish well. Rarely my goal personally unless I know I’ll be microbeveling the edge for the foreseeable future. Then I realistically only have to polish it the one time

[@_BLANK_BLANK]

@@EngineersPerspective701 I do it for customers. Usually not on anything crazy. The near mirror that the kitayama 8k gives after a 1k. Followed by stropping is usually more than good enough for them. Tbh when they get their knife back, and see the bevel all shiny, and its gliding through hairs they're usually pretty impressed. I've messed around with different progressions, and I've found the grit rating isn't too important. What is, is that the stone can remove the scratches from the previous stone in a timely manner. Like the 300 to 1k. I use a king 300, and either a shapton 1k, or a king hyper 1k soft. Either way the king leaves scratches a bit finer than its rated imo, and both of those 1k stones are pretty efficient at removing those scratches (with the king winning in speed).

[@EngineersPerspective701]

@@_BLANK_BLANK Absolutely. Grit rating is only a guide not a guarantee. Case and point is the shapton pro 5k is actually more like a 3K chosera in actual abrasive particle size. But due to binders they still don’t even finish the exact same. Often I personally won’t even be looking to remove all the scratches from the previous grit because I’m not looking for a pretty finish. Can even get a halfway edge. Like a DMT fine followed by a 800F Venev OCB diamond waterstone can have a lot of refinement but keep wild bite from the diamond plate