Taking sharpness to another level.

[Vintage Engine Repairs]

This is just for fun, I spent a few minutes on a tooth taking it up to 10,000 grit, just to see if it was possible. It was for proof of concept rather than with the intention of a perfect edge, finish and angle geometry.

I can do a lot better and intend to when I do the chain proper, but thought I’d start a thread documenting the process / results.

it may be a total waste of time and not show noticeable improvements in the wood, alternatively it could be great.

Of course this wouldn’t be realistic to do for a fire wood saw, it’s too labour intensive, but for a fun experiment I’ll give it a go - I’ll test it in soft wood initially, I expect that to be where the differences will be most notable.

it’s going to take some time to do but as and when I’m in the mood I’ll do a tooth at a tine

As a point of reference you can compare the gullet of the tooth to the same area by the raker

Quick video of a filed tooth vs this tooth, it’s sharp kind of, but with time and care it will be far far sharper. It could very well be the burr on a normal filed tooth that’s actually causing it to rip and catch. I’ll test that too.

 

[user 122190]

I have done things like this with the ax and with lots of knives, and the results are spectacular and short lived.

 

[Vintage Engine Repairs]

I have done things like this with the ax and with lots of knives, and the results are spectacular and short lived.

I politely disagree here, as a professional tool sharpener, I can say with confidence a the longevity of an edge is a combination of the apex angle, steel and heat treat and not a reflection of how refined you take the edge. If fact for typical high carbon steels a fine edge lasts longer than a coarse edge

The best demo of this is from a carving knife I designed and had made from z-wear by the finest knife maker I know, I sharpened it when it first arrived and even after over 30 hours of carving wood I was still able to cut a single unsupported hair with only stropping.

https://www.instagram.com/p/CHC9jCqDA3l/?igshid=1s3gwj8rdotd3
Comparatively, a chainsaw tooth is very soft and poor quality steel / treatment to a high quality custom made knife, so I don’t expect it to last long, but then again part of me thinks it will last longer than a filed tooth. I’ll share findings and videos here in time.

 

[user 122190]

I bring out my best knives to skin game. The blades cut so clean with so little effort that it is spectacular. As the hanging deer is finishing up the knife cuts great, BUT it is nothing like it was freshly off the sharpening jig.

My best knives are Buck and Kershaw Knives, and if their steel is not sufficient to hold a polished edge then, well, that is something else...

Granted i have never tried to cut a single unsupported hair. Not sure a hunting knife is made for such things. Like I wouldn't shave with a big Higgens III that I have done recently and is spooky sharp, that I wouldn't allow anybody to touch the cutting edge.

 

[user 122190]

@Gaudaost

Are you familiar with Eafengrow knives. I picked one up several months ago, sharpened/polished it but have yet to actually use it. Gorgeous knife and took the edge very quickly. Unfortunately, is just a bit to large to for an EDC knife. Question is about the steel which is called D2. I took a materials engineering class during my undergraduate studies, but never really followed up on it afterwards.

Here is the description of D2

D2 STEEL BLADE​

Reliable D2 stainless steel blade, provides razor sharp for ultimate precision cutting performance with strong toughness and excellent edge retention

Does that relate to real world application or is it just a marketing ploy?

 

[Vintage Engine Repairs]

I bring out my best knives to skin game. The blades cut so clean with so little effort that it is spectacular. As the hanging deer is finishing up the knife cuts great, BUT it is nothing like it was freshly off the sharpening jig.

My best knives are Buck and Kershaw Knives, and if their steel is not sufficient to hold a polished edge then, well, that is something else...

Granted i have never tried to cut a single unsupported hair. Not sure a hunting knife is made for such things. Like I wouldn't shave with a big Higgens III that I have done recently and is spooky sharp, that I wouldn't allow anybody to touch the cutting edge.

View attachment 889273
View attachment 889274

View attachment 889279

I don’t want to go too far off topic, but Seeing as you love your knives. think you’ll find Kase Knives and his process interesting, his last sentence summarises up what he’s saying in the paragraph. People send their most prized knives from the most well known manufactures to him to have them heat treated correctly, the difference in sharpness and edge retention mind blowing. None the less, hang around and we’ll learn together what can be achieved on chain, it should be a fun journey and experiment. Don’t hesitate to drop me a PM and we can chat more about knives, like you, I love them too. I fear this thread may go off topic otherwise.

https://www.kase-knives.com/start/insights/heat-treat-steels/

 

[Philbert]

Following, since this is something I thought about many times.

A razor blade is very sharp, compared to a saw chain cutter edge, but it does not get slammed into tree bark 20 times per second, in normal use.

Very smooth edges might yield a smoother cut in applications where that is important (e.g. milling), but the consistency across the cutting edges of the other 30, or so, cutting edges that follow in rapid succession, may be more important than the degree of polish attained.

Saw chain is not a single edge, like a knife.

BTW, I have also mused in these threads about “serrated“ edges for cutting certain types of wood.

Philbert

 

[Vintage Engine Repairs]

Following, since this is something I thought about many times.

A razor blade is very sharp, computing a saw chain cutter edge, but it does not get slammed into tree bark 20 times per second, in normal use.

Very smooth edges might yield a smoother cut in applications where that is important (e.g. milling), but the consistency across the cutting edges of the other 30, or so, cutting edges that follow in rapid succession, may be more important than the degree of polish attained.

BTW, I I have also mused in these threads about “ serrated“ edges for cutting certain types of wood.

Philbert

I think you are spot on Philbert about angle and geometry being so much more important than polish / extreme sharpness for performance.

I brought the fg2 after hearing about yours and @rogue60 advice about tooth length and accuracy consistency as well as a way to reset angles if I wander overtime with free hand filing. I think doing the job on the fg2 will give superior results to what I could manage freehand for the reasons you mention above. This said, I couldn’t get on with it last time, but having been given some advice from a friend, I’ll try a slightly different approach.

 

[buzz sawyer]

This is just for fun, I spent a few minutes on a tooth taking it up to 10,000 grit, just to see if it was possible. It was for proof of concept rather than with the intention of a perfect edge, finish and angle geometry.

I can do a lot better and intend to when I do the chain proper, but thought I’d start a thread documenting the process / results.

it may be a total waste of time and not show noticeable improvements in the wood, alternatively it could be great.

Of course this wouldn’t be realistic to do for a fire wood saw, it’s too labour intensive, but for a fun experiment I’ll give it a go - I’ll test it in soft wood initially, I expect that to be where the differences will be most notable.

it’s going to take some time to do but as and when I’m in the mood I’ll do a tooth at a tine

As a point of reference you can compare the gullet of the tooth to the same area by the raker

Quick video of a filed tooth vs this tooth, it’s sharp kind of, but with time and care it will be far far sharper. It could very well be the burr on a normal filed tooth that’s actually causing it to rip and catch. I’ll test that too.



View attachment 889268

Dang if you don't come up with some real interesting ideas!
I'll throw in my 2 cents. I've been woodcarving for 20+ years using knives, large gouges, palm gouges, etc., in many types of wood - walnut, cherry, catalpa, maple, basswood, cottonwood bark. I polished all my edges with green rouge on a buffing wheel until a cut on end grain leaves only smooth, shiny wood and no fine tear-out lines. The polished edge glides more easily and lasts longer because you have removed the microscopic serrations on the edge. I do believe a polished chain would cut more quickly and smoother. This might be beneficial for chainsaw carving or a hot saw. Even if it lasts only a short time, it should speed it up a little.

 

[trains]

 

[Bob Hedgecutter]

Someone is going to need a tinted visor for his helmet.
All those polished surfaces of saw cases and chain gullets, coupled with the strong Aussie sun, may well lead to blindness.

 

[kielbasa]

This is awesome - looking forward to what we end up learning here!

 

[Andyshine77]

One of the issues with saw chain is the fact it's chrome plated, to get the tooth truly sharp one must remove some of the chrome. To actually get the working coroner sharp, you'll need to square file the chain, that will net the biggest gain with the correct angles. Now the other thing to improve efficiency and smoothness is to stone the side plate, this helps even the teeth out from tooth to tooth. When you cut with the chain that's been stoned, the wood will have a smoother finish with less ridges. The guys that make race chain may chime in with better knowledge than I.[emoji111]

 

[KASH]

Gaudaost I have to say when you set your mind to a task you give it your all.I enjoy your posts and learn a bit too.
Carry on your doing great in my book.
Kash

 

[Vintage Engine Repairs]

Gaudaost I have to say when you set your mind to a task you give it your all.I enjoy your posts and learn a bit too.
Carry on your doing great in my book.
Kash

That’s really kind of you to say so mate, thank you!

 

[Vintage Engine Repairs]

So I just filed a couple of chains, .325 one on the fg2 and 1 freehand. Neither will cut paper as in the video in post #1 coming just off a file. I’m going to take these two out shortly and see if I can match the fg2 results freehand (without obsessing over every tooth). The new stihl chain out the box I matched in cut times just fine, but a filed tooth feels like a finer edge than what comes from the factory. Kept both around the original specs as much as I could. I think it’ll be very close either way. Technically the fg2 should win, the teeth are even length (while the hand file chain aren’t even close to the same length) and the angles are very consistent with the fg2 of course (I tried to stay consistent hand filing )

I put the blue line in as a point of reference for profile for myself earlier, but either way here are the two teeth:
Please ignore the rakers, they haven’t been done on either chain yet.


hand file tooth:



Fg2 Jig filed tooth:

 

[Ben Hur]

I bring out my best knives to skin game. The blades cut so clean with so little effort that it is spectacular. As the hanging deer is finishing up the knife cuts great, BUT it is nothing like it was freshly off the sharpening jig.

My best knives are Buck and Kershaw Knives, and if their steel is not sufficient to hold a polished edge then, well, that is something else...

Granted i have never tried to cut a single unsupported hair. Not sure a hunting knife is made for such things. Like I wouldn't shave with a big Higgens III that I have done recently and is spooky sharp, that I wouldn't allow anybody to touch the cutting edge.

View attachment 889273
View attachment 889274

View attachment 889279

 

[Mike Kunte]

So I just filed a couple of chains, .325 one on the fg2 and 1 freehand. Neither will cut paper as in the video in post #1 coming just off a file. I’m going to take these two out shortly and see if I can match the fg2 results freehand (without obsessing over every tooth). The new stihl chain out the box I matched in cut times just fine, but a filed tooth feels like a finer edge than what comes from the factory. Kept both around the original specs as much as I could. I think it’ll be very close either way. Technically the fg2 should win, the teeth are even length (while the hand file chain aren’t even close to the same length) and the angles are very consistent with the fg2 of course (I tried to stay consistent hand filing )

I put the blue line in as a point of reference for profile for myself earlier, but either way here are the two teeth:
Please ignore the rakers, they haven’t been done on either chain yet.


hand file tooth:

View attachment 889422

Fg2 Jig filed tooth:

View attachment 889421

Lovely looking C-shape there! Should cut extremely well!

 

[Canyon Angler]

I bring out my best knives to skin game.

Same here. My standard deer-skinning kit is a crosscut saw or sawzall for the aitch bone, a serrated Dexter fish knife for the sternum, and for skinning, a Case sheath knife (mine is made of some of the nicest steel I've seen) and a laminated Swedish Frosts Mora, which holds an edge better than anything I've found -- the edge portion is a piece of super-hard steel (IIRC > 65RC) and although it'll chip if you drop it really easily, since it's so hard, it'll hold an edge forever. That hard piece of steel is sandwiched between two layers of softer, tougher steel so the knife won't break into pieces if you drop it or try to bend it...I've got one or two laminated "white steel" Japanese chisels for woodworking that are also super nice to work with...not sure I'd ever bother sharpening a chainsaw to 10k grit though -- I don't even do that with my plane irons or chisels! What color jeweller's rouge does one use for 10k grit?

 

[Canyon Angler]

If fact for typical high carbon steels a fine edge lasts longer than a coarse edge

So....microbevels actually decrease edge-holding ability? That's a new one on me. Maybe we should be using razor blades on our lawnmowers and axes. Even microtome blades -- used for cutting microscopically-thin slices of animal tissue for histology -- have secondary bevels.

I guess the "finest" edge you can get is the wire edge that forms when two planes intersect in steel ... but the wire edge doesn't last very well at all. You can break it off with your finger. I'd rather knock it off with a microbevel (jeweller's rouge on a piece of MDF) than let it break off on its own, since the microbevel will be more durable and will be sharper than the jagged edge that's left when the wire edge is broken off the first time you use the tool.