Polished vs toothy edges

[Razorsharp-Travis]

Polished looks pretty, Cuts great, but they may as well be dull when its down to a working edge, yeah they still cut, but there is so little aggression. Once I lose my hair whittling polished edge and have worn it down to a kinda shaving edge, by then theres jack-all bite. Coarse edges keep their bite and just plain cut longer IMO. I do a polished edge and microbevel with a coarse microbevel. Kinda hard to see the microbevel on this pic. Its a 0.1 micron backbevel that was done to treetopping, (playing with the edge angle on m390) then it was microbeveled extremely lightly at 600 grit and stropped on plain denim lightly, with a few finishing passes on 0.5u loaded leather. Great cutter, like it more than the 0.1u polished microbevel I had tested out

 

[Wet Noodle]

The idea of microserrations just seems sketchy to me for anything harder than meat. It's only steel, and we're talking about steel about foil's thickness if not less. Those serrations just sounds like they would break off into wood almost immediately.

You'd get exposed to more metal particulates in the air driving to the mall. A quick strop, even on your jeans, would take off the vast majority of any metal that might contaminate anything. Even if you didn't clean your freshly sharpened/toothed edge you'd need a forensics lab to find any metal left behind by your blade.
Do some tests on different materials with a polished edge and a toothed edge and see if you can find any trace of leftover metal.
Let us know the results.

 

[Cynic2701]

Polished looks pretty, Cuts great, but they may as well be dull when its down to a working edge, yeah they still cut, but there is so little aggression. Once I lose my hair whittling polished edge and have worn it down to a kinda shaving edge, by then theres jack-all bite. Coarse edges keep their bite and just plain cut longer IMO. I do a polished edge and microbevel with a coarse microbevel. Kinda hard to see the microbevel on this pic. Its a 0.1 micron backbevel that was done to treetopping, (playing with the edge angle on m390) then it was microbeveled extremely lightly at 600 grit and stropped on plain denim lightly, with a few finishing passes on 0.5u loaded leather. Great cutter, like it more than the 0.1u polished microbevel I had tested out

I'd hazard a guess that if you put a narrower angle on that, you'd change your tune. If the scale on the left side is in millimeters, then it would appear that your bevel is only ~1 - 1.5 mm wide. Of course, much depends on the thickness and height of the blade, but I would suggest that you really don't have a very thin bevel on that knife.

Here's a picture of a knife I put a 20 degree (10 per side) bevel on, with a 30 degree (15 per side) microbevel down to 1 micron:

I can cut cardboard and nylon strapping for a long time with that edge. In my uses I've found that a coarse edge with very thin bevels doesn't last quite as long as a polished one.

 

[killgar]

Personally, I think that stropping/polishing an edge is for shaving, like a straight-razor. For my personal work-related cutting (plastic, natural ropes, rubber) a medium grit hone is enough to give me an edge on my knives that will cut great all day. I don't really see the point of using hair-shaving as a test of sharpness, unless of course you shave with your knives. A particular edge might be great at shaving hair from your arm, but might really suck for other needs.

The way I see it, personal experience will teach you everything you need to know about what type of edge YOU need on your knives. If a polished edge works great for you and your individual needs, or if a toothy edge works better for you, then you will have your answer. Knife use, and what type of edge will work best, are very personal, individual things. What works best for one person might not work well for others.

 

[singularity35]

I'd hazard a guess that if you put a narrower angle on that, you'd change your tune. If the scale on the left side is in millimeters, then it would appear that your bevel is only ~1 - 1.5 mm wide. Of course, much depends on the thickness and height of the blade, but I would suggest that you really don't have a very thin bevel on that knife.

I can cut cardboard and nylon strapping for a long time with that edge. In my uses I've found that a coarse edge with very thin bevels doesn't last quite as long as a polished one.

I'm not Travis but I know the guy(some of us knifenuts have a chatroom we frequent) from chat for a long time now. We discuss and learn from each other. Travis is a mature 17 years old who is really good with his hands and has minimal sharpening gear(well except for a belt sander, he uses a sharpmaker, and sandpaper) who looks to have promise as a knifemaker. Travis has reground that Caly and it's now thin. That's the reason for the narrow bevel. IIRC, he has the bevels set at around 8 dps.

 

[me2]

The idea of microserrations just seems sketchy to me for anything harder than meat. It's only steel, and we're talking about steel about foil's thickness if not less. Those serrations just sounds like they would break off into wood almost immediately.

You're on the right track here, but it's not that clear cut. A coarse edge cuts soft materials longer when slicing motions are used. This is most knife use. However, as the material being cut gets harder, or the bevel angles get more acute, a more polished edge begins to work better. Use also helps figure out what you like and what will work best for your cutting. I have always preferred a polished edge with a higher push cutting sharpness. For chopping knives and machetes, a polished edge works better, but this is push cutting. Most knife use falls in the middle, and either one can work well, or you can just go with a medium grit finish. I have always like a Norton Fine India stone finish (about 300 to 400 grit US), and now that I have a waterstone instead of the Norton combo stone, the 1000 grit (Japanese) side is nice. Most knives I carry stop at 1000 grit waterstone or the Sharpmaker medium (gray/brown) rods. These edges can treetop hair and still have plenty of aggression. My choppers get sharpened and power stropped on my belt sander.

 

[Wet Noodle]

I'd hazard a guess that if you put a narrower angle on that, you'd change your tune. If the scale on the left side is in millimeters, then it would appear that your bevel is only ~1 - 1.5 mm wide. Of course, much depends on the thickness and height of the blade, but I would suggest that you really don't have a very thin bevel on that knife.

Here's a picture of a knife I put a 20 degree (10 per side) bevel on, with a 30 degree (15 per side) microbevel down to 1 micron:

I can cut cardboard and nylon strapping for a long time with that edge. In my uses I've found that a coarse edge with very thin bevels doesn't last quite as long as a polished one.

I can't get good results on my CRK knives with that kind of bevel. I'll fold the edge pretty quickly. CRK knives in particular, for me, do better with a toothed and less steep bevel than the harder variants of the same steel that other manufacturers use.
Spyderco seems have higher hardness and can take steeper angles than most of my other brands.
Benchmade, for me, has to be a bit less steep and toothier.
ZT seems to take and hold a steeper bevel and I like 'em toothy.
CRK knives... way softer than anything I find from anyone else - gotta be a more 'bluntish' edge for me to get the most out of the edge before I have to dress it again.
I've put in hundreds of hours trying different brands, different hardness standards, different bevels and different finished edges (polished/toothed).
Regardless of the steel, I approach different brands with a different sharpening strategy.
Perhaps I'm delusional.

 

[Swoop03]

You all have good points, it all comes down to opinion...in my opinion. Try different edges out and just go cut and slice things you would encounter on a daily basis. For me it would be boxes, paper, strings, food prep and thats pretty much it for a typical edc. I find that if I stop anywhere from 600-1000 grit depending on the steel then strop it seems to round off those micro serrations. Kershaw serrations come to mind for a large scale demonstration I guess. My edges still bite a fair bit, but they also push cut decently as well. Though I tend to slice more. Just try out new things until you get what works for you. There is something for everyone.

 

[marthinus]

My advice: Experiment with both and stick to what works for you.

 

[Razorsharp-Travis]

I'd hazard a guess that if you put a narrower angle on that, you'd change your tune. If the scale on the left side is in millimeters, then it would appear that your bevel is only ~1 - 1.5 mm wide. Of course, much depends on the thickness and height of the blade, but I would suggest that you really don't have a very thin bevel on that knife.

Here's a picture of a knife I put a 20 degree (10 per side) bevel on, with a 30 degree (15 per stide) microbevel down to 1 micron:

I can cut cardboard and nylon strapping for a long time iwith that edge. In my uses I've found that a coarse edge with very thin bevels doesn't last quite as long as a polished one.

Haha I should clear myself up. The edge I showed earlier is on a reground paramilitary 2 in m390 with a 10 degree backbevel and super small 600 grit microbevel at 14-15 degrees. When the polished edge goes down a few steps in sharpness, it doesn't feel sharp, or slice well, even if it shaves, in that same amount of cutting, my coarse edge may shave and still " feel " sharp and keep a lot of slicing aggression.

Same knife before regrind, also hasa 10 degree back, 15 micro at 600

 

[Razorsharp-Travis]

I'm not Travis but I know the guy(some of us knifenuts have a chatroom we frequent) from chat for a long time now. We discuss and learn from each other. Travis is a mature 17 years old who is really good with his hands and has minimal sharpening gear(well except for a belt sander, he uses a sharpmaker, and sandpaper) who looks to have promise as a knifemaker. Travis has reground that Caly and it's now thin. That's the reason for the narrow bevel. IIRC, he has the bevels set at around 8 dps.

You're close buddy, this was the para,. Similar geometry , but 2dps fatter

 

[singularity35]

You're close buddy, this was the para,. Similar geometry , but 2dps fatter

Hehehe, my bad. Looked just as good as the SB Caly too.

 

[Ankerson]

The interesting thing is on the polished edge thing is that from my own testing using the same Spyderco Military in S90V at 60 HRC as an example.

Polished edge 6K EP = 260 cuts on 5/8 rope to 20 LBS of down force.

Coarse edge 400 grit Congress SIC = 460 cuts on 5/8 rope to 20 LBS of down force.


While the polished edge was done at 260 cuts the coarse edge was still at 16 LBS.

And both edges were at 15 LBS at 100 cuts.


And this is testing the same knife with 15 degrees per side edge geometry.

This has been typical of what I have seen across the board in my testing of various steels, but that's draw cuts on 5/8" manila rope.

That's after a lot of testing to see what the optimal edge finish would be based on my own testing for efficiency and edge retention.

 

[singularity35]

The interesting thing is on the polished edge thing is that from my own testing using the same Spyderco Military in S90V at 60 HRC as an example.

Polished edge 6K EP = 260 cuts on 5/8 rope to 20 LBS of down force.

Coarse edge 400 grit Congress SIC = 460 cuts on 5/8 rope to 20 LBS of down force.


While the polished edge was done at 260 cuts the coarse edge was still at 16 LBS.

And both edges were at 15 LBS at 100 cuts.


And this is testing the same knife with 15 degrees per side edge geometry.

This has been typical of what I have seen across the board in my testing of various steels, but that's draw cuts on 5/8" manila rope.

That's after a lot of testing to see what the optimal edge finish would be based on my own testing for efficiency and edge retention.

Thanks Ankerson, that's pretty good data that you spent your time and money on and it's generous of you to share that so freely.

 

[i_am_ninja]

The interesting thing is on the polished edge thing is that from my own testing using the same Spyderco Military in S90V at 60 HRC as an example.

Polished edge 6K EP = 260 cuts on 5/8 rope to 20 LBS of down force.

Coarse edge 400 grit Congress SIC = 460 cuts on 5/8 rope to 20 LBS of down force.


While the polished edge was done at 260 cuts the coarse edge was still at 16 LBS.

And both edges were at 15 LBS at 100 cuts.


And this is testing the same knife with 15 degrees per side edge geometry.

This has been typical of what I have seen across the board in my testing of various steels, but that's draw cuts on 5/8" manila rope.

That's after a lot of testing to see what the optimal edge finish would be based on my own testing for efficiency and edge retention.

agreed. Until someone can find some better objective evidence I think that settles it (at least for s90v?). The results are far from marginal so I think ill transitioning from polished to toothy.

 

[Razorsharp-Travis]

Toothy works better for every steel Ive used. Though i still carry the Superblue caly with a polished edge cause that get so sharp with a lot of bite with those fine little W carbides

 

[Ankerson]

Thanks Ankerson, that's pretty good data that you spent your time and money on and it's generous of you to share that so freely.

I used S90V because I just did that M390 vs S90V comparison not long ago and posted the data with the coarse edges so i figured I would just post what I got for this thread.