Making a scary sharp edge - for knives, it's often about the metal!

[Will Blick]

One problem with becoming a Neander in ww.....it tends to spill over into your other life. I have always been relatively happy with my kitchen knives.... yet, it always bothered me I could not get kitchen knives as sharp as my chisels and plane blades. I was never sure why, I always assumed it was the metal...even though I thought they were high quality metal knives from Henkel. I have water stones up to 30k, so I really give them careful treatment, but yet, still they barely can shave the hair from my arm....

Then, Bridge City lured me in with their current sale on high quality Japanese made Hattori Kitchen knives.... so I bought this one...




Well, now I understand the value of having the best metal...this knife was so sharp out of the box, it was like a single edge razor on my arm hair....then, I stropped it, and sheeeesh, now I understand what sharp is all about.

I am no expert at this, but I will have to assume its the metal which makes all the difference in sharpening.... if you have inferior metal, it will supersede your sharpening skills. If you have the right metal, it seems even mediocre sharpening stills will shine. I am curious how others more experienced react to this.... am I on track? \

BTW, if you want an amazing knife (s), I would highly recommend these, and the BC sale price is very competitive. This is not Hattoris best knives, but for the avg Joe in the kitchen, its an heirloom knife for sure...

[Henk Marais]

On Sunday afternoon, I took the knife block to the shop and treated it. I thought while I got all the knives there, I will run them over the stones a bit. I was very disapointed with the result and still made a joke with SWMBO and said that I will have to use the chisels when next we braai (You guys call it a BBQ).
I also came to the conclusion that it is the type of steel. They also do not keep the bit of an edge very well.

[Joel Goodman]

My experience has been that old fashioned carbon steel knives (the kind that rust) take a great edge easily with all sorts of stones. The new Wustoff and similar stainless steel knives seem to respond better with diamond stones. I'm glad plane irons aren't stainless!

[Hank Knight]

I think the alloy used in most modern kitchen knives is designed more for it's stainless/rustproof characteristics than for it's edge-holding properites. I don't know the alloying ingredients, maybe some of our metalutrgical gurus can speak up here. I do know that you could get a great edge on the old carbon steel blades my mom had in her kitchen drawer. You couldn't put those knives in a dishwasher like you can the modern ones, but you could shave with them in a pinch.

Hank

You beat me to it, Joel.

[jeremy levine]

My experience has been that old fashioned carbon steel knives (the kind that rust) take a great edge easily with all sorts of stones. The new Wustoff and similar stainless steel knives seem to respond better with diamond stones. I'm glad plane irons aren't stainless!

This is the crux of the knife metal debate. If you look most high quality knife manufactures offer carbon steel , "high carbon steel" and stainless.

Stainless hard to sharpen easy to keep clean.
Carbon Steel easy to sharpen hard to keep clean.
"High Carbon" ... trys to sit in the middle.

[Will Blick]

Joel, good point about plane blades. I guess since they rust, they would not be useful for kitchen cutlery.... in addition, a plane blade has mass, a kitchen blade does not, so this will also influence the type of metal. On the History channel, they had a special on blades.... it focussed mostly on shaving razor blades, and even in that area, I marveled at how many processes the metal must go through to create a sharp edge. Interestingly enough, these edge engineers also test their forearm hair during the sampling process. It turns out, that shaving your forearm hair is a very stringent test for any edge.... mainly due to the hairs resistance to cut.... protein in the hair is very resilient.


I used to always read about how a specific metal is made.... If you read up on these Hattori knives, they emphasize the painstaking process of producing the metal.... I used to think this was just hype to sell expensive knives, but now I have a full appreciation for the science of making metal that can create and hold a razor sharp edge.

The best part of this learning experience for me is.... I will no longer spend forever sharpening and re sharpening certain, supposed, high quality knives that don't produce a satisfactory edge....instead, I just ordered more Hattori knives from BCT.... its all about the metal ... and I think being a Neander, we are spoiled by the ease of sharpening plane and chisel blades, and once you understand whats possible, you get frustrated with inferior edges :-) As often is the case, the solution lies in spending more money.

BTW, the higher end Hattori knives are up to 3x more expensive than the lower line which BCT has on sale. I would love to experience one of those knives. Oh yeah, also, BCT is offering free shipping on the knives for a limited time, if you have the promo code, which I don't have handy... I have no association to BCT.