Polished edge ?

beluga

beluga

Joined
Nov 17, 2001
Messages
1,957
Guys, I read the thread about mirror polish edge in this forum (most excellent jobs everyone! kudos to you), and I'm a bit curious if mirror polish edge will do well in a cutting task that requires micro serration, such as cutting rough materials (hemp rope, etc.). What's the purpose in mirror polishing your edge ? I tried mirror polshed my Spyderco military in BG-42, but the result was I had difficulties in cutting ropes or even paracord. Does mirror polish only work well with certain steel ?

Please share your thought, but no flame war.
 
i'm polishing most of my blades right now
last I did was GEC 73, convexed and polished the edge, cuts paracord by push cut or by regular vut easily, slices 3mm leather without any offort

for me i'ts the best, have yet to ytry it on rope but I think it will cut it
 
the finer the medium used to sharpen, the finer the edge.

the apex edge pro comes with 1000 grit paper, and 2500 is available. either will put a very fine, mirror edge on a knife.

its not a matter of it just being "shiny", but rather using the finest grained media possible to get the finest edge.
 
With my woodworking tools I put them on a water stone as high as 8000 grit. I don’t think that is practical on a knife however the cutting edge is so shiny it reflex like a mirror.

MORIMOTOM said:
its not a matter of it just being "shiny", but rather using the finest grained media possible to get the finest edge.
Click to expand...

What you are doing when you "polish" a edge is taking all the micro bumps out (mostly anyways). If you blade is truly sharp you will not have difficulty cutting synthetics.

Some metals will not get this sharp. I have not had good luck with 440a or b. I have great luck with 1095 and D2.

With my blades i sharpen up to a 1200 grit then often use a strop to polish.

This might be someone helpful: http://www.hocktools.com/sharpen.htm
 
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Yeah, the more polished an edge is the less toothy it is. So an edge with a good high polish will be better at things like push cutting, and shaving. It also excels at chopping, smoother less serated edge is less prone to chipping and damage.

True a more toothy edge seems to bite more into some material, but you can achieve a truely hair splitting edge useing the super fine grits that are needed to get a true mirror finish, and once that leavel of sharpness is acheived your edge will bite into almost anything with relative ease. IMHO :thumbup:
 
i put a high polished mirror finish on some of the knives i make with a convex edge or half convex edge (if they are a chisel grind). i have noticed some material is a little harder to cut with a highly polished edge like beluga stated. the steel i use is 1075 with the hardness between 63rc to 65rc.
 
en0 said:
With my woodworking tools I put them on a water stone as high as 8000 grit. I don’t think that is practical on a knife however the cutting edge is so shiny it reflex like a mirror.



What you are doing when you "polish" a edge is taking all the micro bumps out (mostly anyways). If you blade is truly sharp you will not have difficulty cutting synthetics.

Some metals will not get this sharp. I have not had good luck with 440a or b. I have great luck with 1095 and D2.

With my blades i sharpen up to a 1200 grit then often use a strop to polish.

This might be someone helpful: http://www.hocktools.com/sharpen.htm
Click to expand...

Ditto on 1200 and stropping.

In both my experience, and what I have read of the experience of others, a slightly rough edge can work a bit better for utility type tasks like cutting rope etc.

A mirror polished edge with glide through finer slicing tasks (food prep, etc.) a bit easier, and many claim a polished edge will hold the edge a bit longer.

I polish all my edges as per the quote above, and they cut everything I ever need them to cut.

IMO you may fiind a rougher edge will continue hacking through rope etc. a bit better than a polished edge after it dulls a bit.

Thinking on a microscopic level, a rough edge will grab and chew on a material, a polished edge will tend to slice and glide through a material.

You may find this an interesting read. The microscopic edge pics are at least interesting.
http://sharpeningtechniques.blogspot.com/

Looking at the very rough edge surfaces, you can see that particles would break away with use, thus supporting the claim that a rough edge will dull quicker. However, if it remains a microscopic rough, jagged, edge it will retain some ability to "saw" through a material, but would not perform as well for finer slicing duties where some finese is desired.

Kevin
 
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In my opinion, different steels & hardness combos need different sharpening jobs. Some work great polished up. Some don't cut very well with a super polish. Some I sharpen to 8, 000 grit, some seem to like 800, to 1,000 grit better.

There again some will change depending on the heat treat. IMO, D2 is one of those.
 
The Mastiff said:
In my opinion, different steels & hardness combos need different sharpening jobs. Some work great polished up. Some don't cut very well with a super polish. Some I sharpen to 8, 000 grit, some seem to like 800, to 1,000 grit better.

There again some will change depending on the heat treat. IMO, D2 is one of those.
Click to expand...

Yeah, I've often heard people claim that polishing up S30V isn't as great because it will "chip out" and become toothy quicker than other steels. Any validity to that?

I like slicing movements more anyway. I've never got anything like a mirror polish, but I've stropped an edge I took off a 1K grit water-stone until it could shave hair without me feeling a thing. However, when it came to actually cutting anything with it, I found it took too much force than my liking to push-cut things, and that slicing with it wasn't too effective either. I kind of like a 50/50 balance between the two, where I can just push-cut something if I can, but if not, apply a little lateral force on it to bring it home with much ease.

Didn't someone do a study that showed polished edges were better for the meat packing industry? I think I remember seeing someone linking to that here.
 
The Mastiff said:
In my opinion, different steels & hardness combos need different sharpening jobs. Some work great polished up. Some don't cut very well with a super polish. Some I sharpen to 8, 000 grit, some seem to like 800, to 1,000 grit better.

There again some will change depending on the heat treat. IMO, D2 is one of those.
Click to expand...


:thumbup::thumbup::thumbup::thumbup::thumbup::thumbup:
 
i will never understand so many peoples interest in rough edges and micro serrations. the higher the polish, the better its going to perform in terms of clean cutting and longevity, its that simple. a razor out of the box is going to cut any medium better than if you took it to a 1000 grit stone, no matter the steel. same goes for every edge unless the bevel is not acute enough, making the edge too broad to actually slice cleanly, only allowing for tearing via serrations of some form. however, even "steeper" 40 degree bevels on knives are super thin and perform better polished.
 
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