Push cutting paper

65535 said:
A polished blade isn't as useful as a ground blade, a ground blade holds its edge better and will cut everyday items better, a polished edge can only push cut because it lacks any serration created during sharpening.
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"You are not supposed to have any teeth on your knife! Sure, every article you have read on sharpening tells you in as many words as possible about the 'microscopic teeth' on your edge and how they cut. It seems that writers are always trying to outdo one another, and pretty soon you have so many old wives' tales back to back that all you end up with is a wild story. Even professional cutlery manufacturers, who should know better, claim the same thing."

John Juranutch
The Razor Edge Book Of Sharpening
pg. 19

I dunno. What to the rest of you think?

Buzz - don't shoot the messenger
 
So, am I to understand that you are saying the claims about "micro serrations" are just bunk, or are you quoting a book that is just saying that.
 
Nosetotail said:
So, am I to understand that you are saying the claims about "micro serrations" are just bunk, or are you quoting a book that is just saying that.
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I think your second guess is what the quotation marks in my post are all about. Are you trying to shoot the messenger? :mad:
 
I never have read an actual sharpening info book or anything of the sort myself, but I personally have given the abrasive properties of a knife blade some time of thought and in my personal conclusion a small amount of abrasive "teeth" if you will, do aid in cutting HARDER material, but definitely don't help soft materials. It is easier to push cut rubbers and soft plastics and it is to push cut plastics where a drawing motion that uses a mild abrasive effect to actually grind off a line of plastic separating the pieces.

Just some of my thoughts.
 
in my experience a truly sharp polished edge will cut anything that needs cut. a "toothy" "working edge" is easier to achieve and maintain and allows a margin of error that a polished edge will not. dulling of a polished edge is more noticeable as well. for example, i have a BM 940 with a polished edge-pro edge micro beveled at 15 degrees. it will slice through seat belts and poly cord with almost no effort. tomatos fall into paper thin slices before the knife even comes near. it binds up trying to slice heater hose for example but so does any knife. that's more a function of the friction on the blade sides. really, isn't sharper better?
 
Hawkings said:
So is that the way to do a push cut, or could you show me a link to where I can see a "True" paper push cut ???
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Here's one I found from a recent thread:
book.jpg
 
For a paper push-cut test, I open a telephone book and fold up about 1/4 to 3/8 of an inch of one edge of a page to a right angle. Put the edge of the blade on the edge of the upfolded edge and slowly increase pressure straight down. If the knife cuts to the bottom of the fold it's sharp enough for me.
This usually takes some real time--most often the first couple of trials only fold the paper down and its back to the leather hone or paper wheel.
Greg
 
The responses are all good, so thank you for that.:)

But what I'm really looking for is a video (Not just a pic.) on how to do a true push cut. So fare none seem to be able to produce that. Starting to make me wonder if its all hype..........:eek: :eek: :eek:
 
buzzard767 said:
I think your second guess is what the quotation marks in my post are all about. Are you trying to shoot the messenger? :mad:
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Sorry if it came across a little harsh. I was just wondering if your experiences matched the reference. So far with my new knife I have to finish with my ex fine to get a real decent edge, but I wanted to try the covetted or perhaps fabled micro serrations. This reference is the first I have seen that encourages against the micro serrations as the best slicing edge. I certainly don't have enough experience to know or take a stand on the subject. I'm rather inclined to think that you could know better.

Also, I have some knives at work that I can get pretty dang sharp with a coarse or ex coarse and I'm still torn on whether to leave that edge on them or polish them off.
 
If this has been mentioned the thread – sorry I missed it. I find the slicing video posted by the original poster to provide as valuable if not more valuable information, in the use of a knife, than the push cut test. I can frequently get a knife to push cut paper and then newspaper or the yellow pages, but it may not be a “perfect slicer”.

So in a slicing test my imperfectly sharpened knife will slice down the paper until it reaches a snag / blur in the blade. The same knife might push cut newsprint along different areas of the blade, BUT if don’t push cut the precise area of the imperfection I won’t be aware to the problem.

Now obviously you can draw the same knife while doing a push cut and learn the same thing, but I thought I’d mention this since many comments seem to indicate that drawing the knife on a push cut is cheating.
 
As long as we're cutting books, I'll post this little video (again) inspired by some other folks here who cut stuff up to demonstrate sharpness and edge holding (Jimmy Fikes in particular). A Busse AK-47 is the cutter:

 
That last Video is pretty impressive. As someone that cuts hundreds of thousands of sheets of paper a day I can appreciate just how sharp that knife must be. I do the same cutting, but with 2,500 lbs of hydraulic pressure behind the blade. And just as an fyi to those trying to cut single sheets, paper has a grain to it just like wood. If you cut with the grain the cutting will go much smoother than cutting against the grain. You can tell which way the grain is running by folding the paper, the fold with the least resistance is the way the grain is running.
 
When I need a sharp edge I test my knifes with push cuts.

I test the sharpness along the complete edge with this method. If there is a part of the edge that is not sharp, the push cut stops just there “automatically”.

I hold a data sheeth paper horizontal in my left hand and the knife, also horizontal in the right hand and the paper and the knife make a X together. I lift up the paper to the edge (and I hold the knife absolutely still) just beside the handle and then I slowly lift the paper upwards and the edge starts to cut the paper. I move the paper slowly along the edge so that every part of the edge make a push cut and I listen to the sound of the cut. (The sound tells me if the edge is ok or if there are any smaller variations on the edge).

If the edge stops cutting - the edge is dull right there where the paper stops.

The edge shall cut the paper all the way, from the handle to the tip –and after the cut, there shall be no paper parts (dust) left on the edge.

I lift up the paper "faster" then I move the paper forwards to the tip, that gives me the control (together with the sound) of the quality of the edge. I cut a A4 paper (data sheath) from top to bottom the longest way. The tip shall cut of the last piece of the sheet.

Thomas
 
Broos said:
As long as we're cutting books, I'll post this little video (again) inspired by some other folks here who cut stuff up to demonstrate sharpness and edge holding (Jimmy Fikes in particular). A Busse AK-47 is the cutter:

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I am definatly impressed!:thumbup:
 
It's such a common thing that your request seems a bit silly. I have a digital Hi 8mm tape, but figuring out how to transfer that to my hard drive then up to the internet is a complete waste of my time in order to satisfy someone's curiousity. I'm far too busy to satisfy this request for such a mundane task. Many, many of us do this all the time to sharpen our edges. To infer that we're making it up, well, believe whatever you like...
 
All of my knives will "push cut" newsprint at least one inch from the hold point. that's touching the blade to the paper and pushing straight down, no slicing!:)

I like polished edges on MOST knives, but my EDC, a Benchmade 710 D-2 is sharpened only with the grey rods of a Sharpmaker, and has a "rough, toothy edge." It still push cuts.:D

I leave the 710 "toothy" because I want a pocket knife that can easily slice through a seatbelt in an emergency.:eek: All of my other knives have a highly polished edge.:)
 
sodak said:
It's such a common thing that your request seems a bit silly. I have a digital Hi 8mm tape, but figuring out how to transfer that to my hard drive then up to the internet is a complete waste of my time in order to satisfy someone's curiousity. I'm far too busy to satisfy this request for such a mundane task. Many, many of us do this all the time to sharpen our edges. To infer that we're making it up, well, believe whatever you like...
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It's pretty common for piano students to learn to play Beethoven's Fur Elise too, and a search on You Tube yields 50 pages worth of videos of people playing it. There are videos of all kinds of things out there, common and uncommon;silly and serious. There are all kinds of useless videos all over the internet. People have taken the time to post videos of cutting books into pieces and slicing multiple sheets of paper. I find it surprising that SOMEONE out there hasn't made a simple little video of their knife performing a push cut on a SINGLE piece of paper at a 90 degree angle. I'm not saying it can't be done. . . I've managed to get one blade sharp enough to pass this test one time. . . but if it's such a common thing I would think that someone would be able to post a video. If anyone around Indianapolis has a video camera that I can use, let me know and I'll make one myself.
 
a push cut means the knife is going moving perpendicular to the edge of the paper. the paper contacts only one point on the blade.
 
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