Plain edge for cutting against hard surface

[Jens Schuetz]

this is the best thread to mention it. one has to come up with a better definition of an EDC than just a small knife sharpened enough to split hair 4 times, and no foreseeable use besides cutting paper or soft plastic. while on a retreat with my extended family, we bought canned goods and then discovered there was no can opener and i was the only one of twelve people who brought a knife. it was my zdp endura; sharpened to 10 degrees either side and stropped to split atoms. well, i either use it or we don't eat the canned items so i cut the cans open and formed visible nicks on the edge from the belly to the tip. one can refuse to take out one's knife for little things like when a troglodyte needs a screw driver or a pry bar but there are things even less desirable than a ruined edge.

so, i re-profiled all my edges to 20 degrees per side: the three militaries, the 3.5 caly, the delica and my endura. it was far easier to sharpen them that way, i was removing less metal, and hopefully the edge will resist deformation better during unavaoidable mis-use.

Next time rub the rim of the tin on a flat stone until the "lid" pops off.
Still liking a thicker edge on my edc's and a thinner one on my vegetable fighters. :thumbup:

 

[BluntCut MetalWorks]

Reasons to design new edge profile...

My sisters wanted good small petty(4.25" blade) knife to go with their nakiri (blue#1, white#2) I bought them while back. So I squeezed time to make three 52100 petties.

At family gathering... Only the knife with Coolibah handle went to a sister. I kept the Lace Ramon and Spalted Mango handled knives because other sisters used these petties against ceramic&glass plates and then left knives at the bottom of the sink pile. Felt slightly depress and defeated. I know, I can insist/train about wipe dry after use but no chance of convincing not to use against hard surfaces. This is more problematic especially with smaller knives.

52100 petties Lace Ramon & Coolibah burl and Spalted Mango handle.

 

[Obsessed with Edges]

^^Gorgeous knives, Bluntcut. :thumbup:

If treated like you described (especially if left in the sink), I'd take those away too. They deserve much better than that.


David

 

[HwangJino]

I also use a plain edge to cut my steaks.

But there are a few of us who can sharpen as well as we do, so serrations probably serve some people well.

 

[olpappy]

I kept the Lace Ramon and Spalted Mango handled knives because other sisters used these petties against ceramic&glass plates and then left knives at the bottom of the sink pile. Felt slightly depress and defeated. I know, I can insist/train about wipe dry after use but no chance of convincing not to use against hard surfaces. This is more problematic especially with smaller knives.

For this type of situation the X50Cr/Krupp 4116 used in German knives, with a durable synthetic like micarta seems to be the best choice of materials. The steel at RC54-56 should be easy to sharpen, stain resistant and not have to worry much about using on hard surfaces. Just sharpen when it gets dull, easy to use with a steel or ceramic rod as well.

6" Henckels utility should do the job.

 

[KennyB]

I went and looked for serrations that are like I was talking about and apparently Wushof makes a knife that has them similar to what I saw...

http://i.imgur.com/BQtJ77g.jpg

To me it looks like the peaks of the serrations will protect most of the edge from impact like normal serrations would, but also remain very smooth and so will not tear stuff. I suppose a person could make them smaller for finer materials?

 

[HeavyHanded]

I worked many years in the printing/paper-converting industry. Among other things we die-cut, "chopped" and slit various substrates at fairly high speeds. The paper or cardboard or film or whatever rides between a hardened steel die/slitter/blade... and a hardened steel anvil roller. The edges are either in constant contact (slitter) or impact many, many times per minute (die or cut-off blade).

There's nothing special about any of this; millions of labels and cereal boxes and all kinds of other stuff are run that way, every single day in factories all over the world.

The number one cause of dulling these tools - by far - is too much pressure. Operated properly, they can cut many thousands of feet and/or make many thousands of impressions between re-sharps. I assure you, the guy running the machine that slits/chops off that stack of printer paper next to you is not stopping every few thousand feet (or even every hour) to hone or swap out his blades... he'd be out of a job.

The digital press I'm currently overseeing runs mill sized rolls and sheets inline - has cut approx 9 million linear feet with the same 2 1/2" diameter cutter. Is not tremendously sharp anymore but can still cut up to and including 14 pt board without a hitch. Rotary blade is spring loaded against a stationary shear bar.
I totally agree re pressure and longevity. This type of cutter produces very little spot pressure.


As for the original premise, I don't believe its possible to have an impact resistant edge that would work well - the design sketch is a good start though. Reminds me of how the bread knife hits the plate with the leading tip as a sacrifice point and the rest is still frightfully sharp. I'll look forward to the prototype!

Martin

 

[BluntCut MetalWorks]

Thanks David!

Constant wet won't be a problem for 52100 steel and stabilized wood handle... oh well, anyway, I enjoy using the Lace-Ramon knife for the last few meal preps.

^^Gorgeous knives, Bluntcut. :thumbup:

If treated like you described (especially if left in the sink), I'd take those away too. They deserve much better than that.


David

 

[BluntCut MetalWorks]

In general, people with decent sharpening skills won't mistreat their edges. And of course, there are ppl want high perf knives that can take mis-use w/o turning a knife into a metal bar.

I also use a plain edge to cut my steaks.

But there are a few of us who can sharpen as well as we do, so serrations probably serve some people well.

~ 440A been around for a long while now. And 99% of the time those knives - I encountered - are in sad shape. Most ppl in my extended family don't sharpen/steeling, except for 1 bro-in-law enjoy grinding sparks with a bench grinder. I found wushtof knives much high quality than henckel various series.

For this type of situation the X50Cr/Krupp 4116 used in German knives, with a durable synthetic like micarta seems to be the best choice of materials. The steel at RC54-56 should be easy to sharpen, stain resistant and not have to worry much about using on hard surfaces. Just sharpen when it gets dull, easy to use with a steel or ceramic rod as well.

6" Henckels utility should do the job.

Good knife but it will tear fibers and bruise fruits/vegies because the apex is scallop (up/down and side/side).

I went and looked for serrations that are like I was talking about and apparently Wushof makes a knife that has them similar to what I saw...

http://i.imgur.com/BQtJ77g.jpg

To me it looks like the peaks of the serrations will protect most of the edge from impact like normal serrations would, but also remain very smooth and so will not tear stuff. I suppose a person could make them smaller for finer materials?

 

[BluntCut MetalWorks]

I agree, thin apex will deform by hard impacts. Thereby need sacrifice point(s) to shield the apex. When sacrifice points wide enough, they can also reduce the edge penetration depth (e.g. cutting board). Ideally the sharp part should only interact with cutting materials, with no or a little impact with backing.

I will try to make a paring knife with the design above -- heheh it will be a while, work deadlines always interfere with my steel mangling fun.

As for the original premise, I don't believe its possible to have an impact resistant edge that would work well - the design sketch is a good start though. Reminds me of how the bread knife hits the plate with the leading tip as a sacrifice point and the rest is still frightfully sharp. I'll look forward to the prototype!

Martin

 

[BluntCut MetalWorks]

I found a dust-collecting 52100 test knife . Did a quick grind then sharpened the edge profile design depicted in previous post.

Thanks for watching & comments.

[video=youtube_share;QWDTn-p-Cbw]http://youtu.be/QWDTn-p-Cbw[/video]

 

[mtangent]

I have found that cutting at an angle, About 70 degrees, to the plate protects the edge somewhat.
Just about impossible to change peoples habits.

 

[Obsessed with Edges]

I have found that cutting at an angle, About 70 degrees, to the plate protects the edge somewhat.
Just about impossible to change peoples habits.

Simple as that is, it's a great idea. A light glancing contact, instead of directly into the edge, could make a difference. :thumbup:

I've often noticed, in watching various cooking shows on TV, a lot of chefs seem to like slicing meat at a diagonal to the cutting surface. Always assumed it's for show (maybe it is; it does look nice), but then again, maybe they've already figured this out.


David

 

[BluntCut MetalWorks]

Yes, it would. Counting on a sharp knife and know what you're doing. We (knifenut) are

An user will instinctively lower the cutting pressure proportional to lowering of the cutting angle (from vertical). thereby reduce apex dulling-impacts with hard surface. If user apply same heavy-sawing pressure at an angle, there will be lateral-force vector which could offset/deform/bend the apex away from center line. Control also diminish along with off-vertical angle.

I have found that cutting at an angle, About 70 degrees, to the plate protects the edge somewhat.
Just about impossible to change peoples habits.

I'm not a chef - so add a few dashes of salt to my 2cents.

For meats & vegies with long fiber, I normally quarter slice/sawn across grain to gain these attributes: enhance tenderness; more appealing presentation; increase slice height; etc...

...
I've often noticed, in watching various cooking shows on TV, a lot of chefs seem to like slicing meat at a diagonal to the cutting surface. Always assumed it's for show (maybe it is; it does look nice), but then again, maybe they've already figured this out.


David

 

[Chris "Anagarika"]

I found a dust-collecting 52100 test knife . Did a quick grind then sharpened the edge profile design depicted in previous post.

Thanks for watching & comments.

[youtube]QWDTn-p-Cbw[/youtube]

Is this the same batch as the champion 52100 in the palm frond test?

 

[BluntCut MetalWorks]

It's in the next batch between that one and the 2 above (coolibah & lace ramon handle). I managed to improve performance on each subsequence batch.... hahahaha it easy to win in a one horse race.

Is this the same batch as the champion 52100 in the palm frond test?

 

[Chris "Anagarika"]

And yet it's collecting dust



Harder to win against plates ... Video download in progress ...

 

[BluntCut MetalWorks]

With less time avail, I tinker with next generation rather than completing previous generation/batch of experimental knives. See pic - I suspended the chef knives:barf: and will jump right into cut new blanks and get a dewar for cryo in LN2. I'll incorporate subtle recurve/hawk-bill profile into this new batch of knives. Will this edge profile works well?

And yet it's collecting dust

 

[mtangent]

For hard surfaces: S2 - sacrifice point #2 - will take the brunt of damaging impact on most usage.

For wood and other materials softer than steel: S2 & S3 will help limit the edge penetration.

S1&s2 protect edge near the thin tip.

For extra protection - you can carefully make sharpen s1+s2+s3 at obtuse angle.



All steaks you can cut on plate. Meal prep on counter/plate/etc.. as you wish.

Would this works - what do you think?

It has just dawned on me that this design is not a plain edge knife. It is essentially two large serrations.

 

[Jens Schuetz]

How about a plain edge combined with a

springy tang?

The tang should provide enough resistance so that the knife can cut through meat and veggies but absorb hard impacts like edge on glass or ceramic.

You'll still dull your knife if abused but not as fast and resharpening is a breeze compared to serrated.