Laminated blades?

[Quy4n8]

Is there any downside to knives made with laminated steel blades? I understand the merits, harder core for holding and edge and softer sides for toughness, but is there any reason to avoid such knives? Thanks.

 

[DGG]

Some blades if not properly forged can separate but this is a rare occurence. Most folks that make these kinds of blades tend to be in the "wizard" category when it comes to steel, heat treating, grinding, etc. of knives. They aren't your cut and polish newbie.

 

[HoB]

More work, higher price, I would think, even though you might recover some of the cost when using very expensive steels for the core, such as ZDP-189. Aside from that, can't really see any drawbacks. It is probably also more difficult to heat treat right.

I would think that if there were any major drawbacks to it the Japanese would have given up on doing it after a while (like after 300 years of bad experience). Tradition goes only so far I would think, once your life depends on your blade, you are probably going with what works best, what you are capable of forging and what you are able to afford.

 

[Jeff Clark]

The idea is great. There is nothing to stop this from being the ultimate blade, except they may not make them the way that you would like. It is pretty common for the core to be up around 60 RC and the outer layers to be down in the 40's. With the outer layers this soft the blades bend easily. They meet a goal of being close to unbreakable, but they are soft and weak compared to more familiar solid blades hardened into the upper 50's.

If you don't really expect to use your knife to split timber you probably want harder outer layers. Then you say, "gee I could just get a blade made from tool steel that is through hardened at 60 RC". What I really want is a blade that has a tool steel core hardened to 64 and simple carbon steel on the outside hardened to 56. You don't tend to find that combination in laminated knives. I'm not sure how compatible the heat treatments would be to get that arrangement.

 

[Habeas Corpus]

What I really want is a blade that has a tool steel core hardened to 64 and simple carbon steel on the outside hardened to 56. You don't tend to find that combination in laminated knives. I'm not sure how compatible the heat treatments would be to get that arrangement.

AFAIK such knives are quite common in Norway, a country that also has a long tradition of laminated blades going back to the vikings. Unfortunately Helle and Brusletto only seem to use stainless steel nowadays, and only Helle uses laminated blades. But there are quite a few knifemakers in Norway that make very nice knives with laminated carbon steel blades.

Hans

 

[Cliff Stamp]

I would think that if there were any major drawbacks to it the Japanese would have given up on doing it after a while ...

Tradition can be a powerful force. Laminates were origionally used to save cost, attach a strip of steel to wrought iron.

Some like Jeff noted are really weak, I have used laminated vs solid stock carbon puukkos, the single steel ones had a far greater scope of work.

In some knives though this doesn't matter, really light use ones for example, but they can be so thin there would be no laminate anyway.

-Cliff

 

[Quy4n8]

Thanks, certainly very enlightening.

Richard

 

[Pocketknife]

Here's a website showing a bunch of inexpensive laminated knives from Sweden, some of which have been around for some time:
http://www.ragweedforge.com/SwedishKnifeCatalog.html
I've had a few of the red-handled 4" blade ones (#S-1, I think). You sure don't worry much about using them, at that price, so they get USED! Fishing, tool box, truck, backpack, etc. I know nothing about the technical details of these blades, but they've served me very well over the years.

 

[Jeff Clark]

The knives that I have used with really soft outer layers have all been scandinavian. One of my first big disappointments in life was the Mora knife I bought as a teenager. The ads said that you could bend the blade to 90 degrees without breaking it. I was dismayed to learn that it was real easy to bend the blade to 90 degrees and it didn't spring back. This was with a laminated carbon steel blade rather than stainless.

If you know the hardness specs on Swedish, Norwegian, or Finnish laminated knives that are harder I like to know the specifics. I'm still looking for that perfect laminated blade.

 

[HoB]

I wonder how hard the outerlayers on the ATS-34/ZDP-189/ATS-34 will get during the heat treat of the core?

 

[misque]

Aside from the issues of bending, there is one other little thing that might put some people off of laminated blades.

The outer skin around the hard layer is much more prone to scratches than a fully hardened blade.

I found this out the hard way when I scrubbed one of my Tojiro-Pro kitchen knives. Fine little scratches all along the soft sides of the knife. Having paid over $125.00 for this knife and having that happen had me doing one of these numbers:

Anyway, I notice the same thing on my Helle "Harding 99". I guess it just goes with the territory.

 

[dannyv]

I am not sure that soft and hard would be the opposite for the laminated blade . I suppose the soft side means 50 as opposed to 65 for the hardness of the core. 50 hardness is not that soft, is it? Unless the soft laminate is 30 as opposed to 65 for the core.

 

[DGG]

Is there any downside to knives made with laminated steel blades? I understand the merits, harder core for holding and edge and softer sides for toughness, but is there any reason to avoid such knives? Thanks.

I think this is referred to as "San-Mai". I found a reference to it on the Cold Steel website.

http://www.coldsteel.com/faqs.html#3

Isn't damascus really a form of lamination? Many times over?

 

[Cliff Stamp]

I suppose the soft side means 50 as opposed to 65 for the hardness of the core.

Some laminates are really soft, using AISI 420 stainless for example so yes they can get below 50 HRC.

-Cliff

 

[tim8557]

The outer skin around the hard layer is much more prone to scratches than a fully hardened blade.

I had the same thing happen with my new Spyderco Caly Jr w/ZDP. Unbelievably sharp but after cutting up a lot of corrugated and double corrugated boxes for the trashman this week, I noticed that even though the edge stayed extremely sharp, the softer sides scratched up a bit. Doesn't really detract from the knife as its a "User" not a "Collector".

I'll go with the superior durability of the ZDP89 and forgive whatever the softer metal is on the overlay.

 

[HoB]

I think this is referred to as "San-Mai". I found a reference to it on the Cold Steel website.
QUOTE]

Actually, the japanese term is "warikomi" when the hagane (core) is surrounded on both sides by Jigane (outer layer). If the Jigane is welded only to one side of the Hagane it is called "kasumi". Cold steel invented the term "san-mai" for their own laminated blades.