Purpose for having high hardness steel laminated to soft outer steels?

N

Naphtali

Joined
May 20, 2002
Messages
148
Original Morseth, and several "top end" knives from custom and limited production makers use three-layer laminated steel blades where its core is very hard (and probably very abrasion resistant) and its outer laminations are softer ductile steels. I have been informed that such blades, when made under rigidly controlled conditions, allow core steels that are normally fragile in demanding use in knives to routinely "stand up" to such use.

I have conflicting attitudes on this information. It sounds as though it should be accurate. At the same time I also suspect laminate steel blades' claimed advantage is mostly hyperbole. I do not include damascus steels in the classification of "laminated steel."

Anyone who has concrete information, please reply.
 
In blades where the secondary bevel is meant to be sharpened on a stone, it allows for easier/faster removal of material.
 
Historically, high carbon steel was difficult to get and lower carbon steel - wrought iron was easier to get. Laminating a high carbon bit in the iron was a sign of a better tool. Today, I do not believe that it offers the same performance advantage that it did centuries ago. But, you can obtain a more wear resistant core with more corrosion resistant and tougher outer layers. But there are bragging rights. Mora's laminated knives carry about 3x the price of their carbon or stainless knives.
 
The above historical answer is 90% of the reason for it.

The second advantage is in the hardness of the blade. It allows for a harder, and lower angle, blade edge with less risk of breaking due to the thin core and tough side laminate. Japanese katana were effective for this reason. Same with laminated Scandi grind Puukko blades.
 
Stacy's right, Bo T NAILED the answer, IMO. High carbon steel was harder to source back in the day. The lamination maximized material usage.
 
Stacy E. Apelt - Bladesmith said:
The second advantage is in the hardness of the blade. It allows for a harder, and lower angle, blade edge with less risk of breaking due to the thin core and tough side laminate.
Click to expand...

I think that's exactly what Murray Carter (and others ) are trying to achieve.
I believe Murray gets 64 HRC and he likes a lower angle for cutting.

here is mine - White Steel laminated with Stainless Steel
and yes I'm a fan of his work.

E9BBD57E-C467-407B-9C8B-E3331F260511_zpsiek1otvl.jpg
 
Last edited:
hsc3_90293:

Wowser! I cannot say how well it works, but if it works like it looks - WOWSER!
 
Here in Japan, where Hitachi steel is used and is on the more expensive side, smiths do still to some extent see it as "wasteful" to make a blade entirely out of it. This is definitely a continuation of the older mentality that Stacy and Bo T are talking about. But I don't believe laminated blades should just be written off as "traditional" without any specific purpose. Although this kind of construction, when used in a katana, would help the blade bend instead of break in battle conditions, this clearly isn't an issue with kitchen knives or wood working tools. I really think the reason this construction is still so commonly used today in Japan is because the culture of sharpening at home is so much more prevalent. In theory, you can keep optimal cutting geometry for longer because you sharpen both the secondary and primary edges on a stone, whereas an all steel knife will sooner have to go back to the belt grinder once you start sharpening the primary edge too high up into thicker blade material.
 
"San Mai generally refers to knives with the hard steel hagane forming the blade's edge and the iron/stainless forming a jacket on both sides. In stainless versions, this offers a practical and visible advantage of a superb cutting edge of modern Japanese knife steel with a corrosion resistant exterior. In professional Japanese kitchens, the edge is kept free of corrosion and knives are generally sharpened on a daily basis. Corrosion can be avoided by keeping the exposed portion of the non-stainless portion of the blade clean and dry after each use."



And then there's "Cool Factor":

 
1. hystorical scarce availability of precious high carbon steel
2. today ease sharpening of the blade
3. today easier maintenance for stainless san mai

The toughness reason: for planes, chisels and knives is just hype. For those implements is actually the edge which is involved and shouldn't be brittle
 
It isn't so much that laminating the steel is just for show, the cutting edge steel itself tends to be expensive to produce and/or procure. White steel and Blue steel both have qualities that are not found in other steel manufacturer's. You can say this sounds magical, but there are many other types of steel that have certain advantages over the other, SG-2, CPM, etc. The advantage of San-mai is that you don't have to pay for an entire blue steel blade, which is not resistant to rust and/or corrosion. Laminating the steel like Tenerbros and SamuraiStuart mentioned, allow the knife maker to stretch the highly sought after steel. It also lowers the amount of maintenance is required to keep the knife in good condition. I wouldn't ever consider buying an entirely white steel blade as a gift for someone who likes to cook every once in a while and has no idea how to maintain it. I would however consider giving a laminated steel as there is significantly less maintenance.

I have a Terayasu Fujiwara Nashiji Gyuto that requires very little to keep it from corroding. I also have a Carter neck knife and a higonokami that both have laminated steels with White. The Carter neck knife is literally the sharpest utility knife I have ever owned.

Sorry for the ramble...
 
On thin kitchen cutlery, a laminated blade with a hard inner core and soft sides is very easy to straighten, as it will easily take a set instead of springing back like fully hardening steel. The last blade I made with 416/1095, after all grinding was done but before finish polishing I straightened it at ambient temp with a brass hammer and a wooden stump. That does not work well on mono steel.
 
You must log in or register to reply here.
Back
Top