Hey All,
I just wanted to get another thread going on things related to handles, methods of attaching handles... all things handles.

My first questions: 
where do you get your corby bolts or other handle hardware?
what is your favorite(s) handle materials?
what would you think is the best material for daily kitchen use?

Designing my next knife, and would like to start doing things proper instead of just making things up.

Thanks,
TW.

I tried the creepy 3 finger test (3-ft) years ago and then developed my own different way that works well for me.  Nonetheless since this came up again here I decided I’d try again.
 
I just sharpened a blade with a A45 Trazact CP 337DC belt ~280 grit, then deburred on the rough side of a plain leather belt and a few swipes on my jeans.    The blade got nice and sharp, 185g on the PT50.  About right for a kitchen knife.  It shaves hair and all of the other obligatory tests without problem.
 
I can put 3 fingers on that blade and press WAY harder that makes any sense to a normal man, and my fingers just slide.  I’m sure I could press much harder, but common sense prevents me.   Pressing very lightly is just not that informative.  I just feels smooth.
 
Now, I know what it feels like to do that on a razor blade.  It has a certain resistance.  For super sharp blades I think I understand the 3-ft.  But that “resistance” is just creepy.  It has that "special" feeling because when your fingers are just bordering on epidermal leakage.  To me the 3ft makes no sense with super sharp blades anyway.
 
It seems to me that a blade has to be sharpened to about 100g or less before the 3-ft test really works well.  100g is sharper than I need or want the blade for edge retention purposes.
 
Here's an image of the blade at ~200X.  It takes a little practice to understand some of the microscope images.  Shadows can make grooves look like a super jagged saw edge.  It can be difficult to get the light just right.  Just zoom in on the image and you can see what looks like a very rough edge is just shadows.  Nonetheless, 280 grit does leave a nice "toothy" edge.  I only post the image to show that this is not a highly polished edge.

So, even though I gave it another honest try, I still don’t get it.  Anyway, it was an interesting experiment to try again, even though the whole idea of the 3-ft is against my better judgment.

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Mark, or anyone else who goes through a lot of belts for that matter, I need to order some lower grit belts.  220 – 320 grits.  I know you have gone through more belts than I probably ever will, and I wonder what your personal choice would be.  AO, Trizact, Norax, Gator, etc.
 
Basic AO’s are cheap, but I don’t like how they aren’t very consistent through their wear cycle.
 
I know it’s an arguable question at best, but I’m curious about your personal  opinion and experience.

I often listen to National Public Radio. Today's On Point program had a fascinating segment about a college professor who teaches a class in very primitive living. The class includes making tools of flint and using these tools to butcher meat. I have included a link. In my opinion, the most interesting part was the final caller. He described himself as a thirty year "flintknapper". He asked how early man knew how to heat treat stones. The professor did not know, but knew that we were heat treating stones to several different temperatures for five hundred thousand years!

Incidentally, when I read Thomas' fascinating posts about the Sami people, I did not know the term. I checked wickipedia and learned that Sami is the preferred designation for the people we commonly call Lapplanders.

Here is the link: (This is audio only. The flintknapper call is at around forty minutes.)

https://dcs.megaphone.fm/BUR6519353648.m...a5503da74e

Ken

Hopefully I'll put a picture here...

few restaurant knives and few super market one and some yard gear

all of the beater knives on 1 x 42......80......220.....600......some leather

yard stuff after i got it cleaned on 220......some scotchbrite..........i hate nasty yard stuff so i clean it all before sharpening.

i have fooled around with many different methods........sisal wheel wth 400grit or emory was my choice.....tried wire wires.....not bad, then red nylon wheel......nice too, but of late i have found Krud Kutter......my knife buddy in tx turned me onto it..... will just about clean most.....with stiff pad or steel wool........for the tuff ones like today i used angle grinder with scothbrite pad........the best
.
.

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When I think of making an edge retention tester many questions come to mind, and when I think about each one it leads to more questions.  At first it seems like a simple idea, but after even a little consideration I think there is a lot more to it.
 
For instance, consider an edge retention test for kitchen knives.  In that case, the material being cut, broccoli or whatever, is not going to dull the blade much by itself.  What dulls the blade is contact with a cutting board.  That contact with the cutting board is mostly in two forms, straight or slightly angled impact from chopping, and slicing across the board surface.
 
Just touching on the many implications of this, one obvious question is, would the test cylinder be made of wood?
 
Consider this sentence from Mike's description of the idea, “The new test stand will be capable of gradually indexing a sharpened edge across the length of a long cylinder as the cylinder is rotated.”
 
Now, I’ve never layered spinach over the edge of a blade and then run a rolling pin over the blade to slice the spinach.  Would it be better if the test cylinder did not rotate and was just dragged over the blade?  Would that yield different results than if the test cylinder was rolled over the blade?

I'm not trying to resolve this particular question here, but rather pose these questions as an example of the complexity of the issues.
 
I’m glad that Mike is considering this a collective effort of the Exchange members.  To me it seems much more complicated than first meets the eye.  Many minds providing feedback and ideas on this will no doubt yield a better result in the end.  I suspect it will be an evolving project.

Welcome to the Edge Retention Pages! After a great start its time to begin some serious discussion. We have all spent a fair amount of time trying to figure out how to make an edge sharp but here we will swap hats and try to discover what makes them dull. In some ways sharpening knives is like making a living and as my dear Dad used to say "It's not how much money you make, its how much you keep." That's pretty much what we would all like to do with a sharp knife edge, hang on to it as long as we can. Of course, edge retention discussions are not limited to knife edges. All of our woodworking and industrial customers have a stake in this as well so everyone is invited to participate.
 
If you have visited the SHARP PAD pages on this Exchange you may be aware of the fact that we are currently building a test stand that will be capable of standardizing many of the test parameters associated with edge retention testing. This test stand, working in conjunction with our edge sharpness test instrumentation, will make for a powerful  team of discovery. The new test stand will be capable of gradually indexing a sharpened edge across the length of a long cylinder as the cylinder is rotated. Rotational speed and direction, and test duration will be adjustable as will the impingement pressure of the edge on the cylinder surface. The surface of the cylinder can present nearly any surface condition we want it to. Hard or soft, smooth or abrasive. We would very much like to make this project a BESS Exchange member project as opposed to an EOU project so how should this first test cylinder be configured?
 
Most testing begins with a premise. For example, when we apply our pressure gauge to a car tire valve stem we have an expectation that some positive level of air pressure exists inside the tire. The test conclusion we are seeking is simply “how much”? With edge retention testing we will be degrading edges with the expectation that their BESS numbers will rise commensurate with the level of degradation. The question before us now is “how will we choose to degrade the edge?” because at least two very clear and possible paths lay before us. We could simply abrade (widen) the edge apex or we could roll the edge apex to the side. Either method will produce higher BESS scores because the rolled edge will manifest itself as a broadening of the edge apex. The type and nature of the test cylinder we first use will determine if the edge is to be abraded or rolled.
 
There are plenty of other questions to be answered with regard to test subject and test parameters but let’s just start here. What kind of test and, therefore, test results will be most beneficial to us?
 
As we proposed earlier, let’s make these tests a product of the BESS Exchange membership. So please open a new thread, or several threads. The thoughts and guidance of every interested member will be much appreciated. Who knows, perhaps a hundred years from now someone will write about us and our work. Our great grandchildren will be proud.

With a metal that can be work hardened, is it possible to have metal fatigue/failure without hardening happening?  Is one always indicative of the other?

Is this a sensible question?

Hello all,
I just wanted to get a thread started on heat treating.
This is one area that the internet seems to have a lot of conflicting opinions.
If you read enough, you can get a pretty good idea about the process, and what parameters are involved.

For my first blade, I was going to outsource the HT, but, I decided that it was better to learn by doing, than having someone else do it.
I bought a used pottery kiln for a pretty decent price, and promptly brought it to the shop and cut a 6" hole in the lid.  (It was a top loader)
After shaping a couple of fire bricks to cover the hole when heating, I started to test with some scraps.

Electric kilns take a long time to get to 1500F!
And cheap thermocouples catch fire around 700F!

How do you measure temperature?
Thermocouple, magnet or other?

What do you use for quench oil?
What temp do you heat your quench oil to, if you do?

Just trying to learn as much as I can before starting blade #2.
Thanks,
TW.