Replies to This Discussion

Permalink Reply by Steve Hanner on August 14, 2012 at 21:32

Interesting Art and I have no actual idea myself. Would not a blade that's hard all the way through be better or does that mean it becomes brittle? And how do you get that layering exactly right?

Permalink Reply by Art Cooper on August 15, 2012 at 8:30

Steve"Hog"Hanner said:

Interesting Art and I have no actual idea myself. Would not a blade that's hard all the way through be better or does that mean it becomes brittle? And how do you get that layering exactly right?

Permalink Reply by Steve Hanner on August 17, 2012 at 17:35

Well having said all that Cold Steel is selling a VG10 blade that has this exact San Mai process. Any chance you will buy one? I would love if you had a chance to review one if you buy it. I am kind of fascinated by the concept actually not knowing if it adds anything other than pretty!

I was just looking at another members photo of a striking San Mai blade. It was custom and not Cold Steel, but looked great.

Permalink Reply by Steve Hanner on August 18, 2012 at 9:36

I also wanted to include this link http://www.iknifecollector.com/photo/my-last-matt-bailey-san-mai?co...

This is a photo iKC Member Guy has posted. Interesting to note how artful this particular blade and knife is.

Permalink Reply by Art Cooper on August 18, 2012 at 9:52

It is a beautiful knife that Guy has.

I currently own 3 blades from Cold Steel: master tanto II, Black Bear sub hilt and a 1796 light calvary saber. The first two have VG-1 San Mai III blades. These are sandwich steel but not that you would notice; that is they are not manufactured to look like any type of Damascus steel blade. They just look like fine knife steel.

All three of these knives are part of my collection and will never be used. So, I cannot really provide any type of review other than to say that I like these higher end Cold Steel blades and from a manufacturing, purpose design and aesthetics perspective they are far and away tops in their class.

Alas, in regard to my understanding of San Mai value in blade strength, I am still where I began, confused.

Permalink Reply by Jan Carter on August 18, 2012 at 10:25

Art,

What I can find that is written in a way I can easily understand is:

A simple way to think of San Mai blade construction is to imagine a sandwich: the center is hard, high carbon steel and the pieces of bread on either side are the lower-carbon, tough side panels. The edge of the blade should be hard to maximize edge-holding ability, but if the entire blade was hard it could be damaged during the rigors of battle (remember this steel was constructed for sword). For ultimate toughness the body of the blade must be able to withstand impact and lateral stresses.

Toughness is generally associated with “softness” and “flexibility” in steel, so that, surprisingly, if a blade is made “tough” the edge won’t be hard enough to offer superior edge holding. San Mai blades provides a blade with hard (higher carbon) steel in the middle for a keen, long lasting edge and tougher (lower-carbon) steel along the sides for flexibility.

What I have done is also ask your question on the iKC Facebook page.  Maybe with all the activity on there from knife builders and makers we can get some more input

 

Permalink Reply by Art Cooper on August 18, 2012 at 10:48

Thanks Jan,

Would this indicate that the "coating" of softer steel on the outside of harder steel gives the entire blade added flexibility? If so, is it by adding "protection" to the more brittle core or something else going on. Interesting.

Art 

Permalink Reply by Jan Carter on August 18, 2012 at 17:29

Art,

Apparently there are several versions of it.  This is Rough Riders information for theirs...

The process starts with a core of carbon steel. Sixteen layers of spring steel are folded around the core, creating a "sandwich" of thirty three layers for strength and rigidity. The steel is then hand finished, giving it the unique appearance.

Permalink Reply by Carl Newton on August 19, 2012 at 21:35

Jan Carter said:

Art,

What I can find that is written in a way I can easily understand is:

A simple way to think of San Mai blade construction is to imagine a sandwich: the center is hard, high carbon steel and the pieces of bread on either side are the lower-carbon, tough side panels. The edge of the blade should be hard to maximize edge-holding ability, but if the entire blade was hard it could be damaged during the rigors of battle (remember this steel was constructed for sword). For ultimate toughness the body of the blade must be able to withstand impact and lateral stresses.

Toughness is generally associated with “softness” and “flexibility” in steel, so that, surprisingly, if a blade is made “tough” the edge won’t be hard enough to offer superior edge holding. San Mai blades provides a blade with hard (higher carbon) steel in the middle for a keen, long lasting edge and tougher (lower-carbon) steel along the sides for flexibility.

What I have done is also ask your question on the iKC Facebook page.  Maybe with all the activity on there from knife builders and makers we can get some more input

 

Permalink Reply by Carl Newton on August 26, 2012 at 0:18

There must be something to it as most if not all of the japanese samuri swords were made this way and we know they last 100's of years.I like the idea.

Permalink Reply by Frank yanez on April 2, 2014 at 17:42

Knives such as san mai knives from cold steel use this layer prosess for giving the knife toughness and hardness so the blade does not break nor chip at the edge.I have a san mai tanto I use as a banger (EDC) and it has never failed me.It keeps a razor edge and does not scratch easy I recommend san mai I am a knife snob and I will say I love it.!!!

Permalink Reply by Frank yanez on April 2, 2014 at 17:49

A blade needs to be hard at the edge or it will not keep an edge but a springe or tough spine is necessary   so it wont chip or break the trick is to get the perfect balance of the two. Makers have been looking the right combonation.
 
Steve Hanner said:

Interesting Art and I have no actual idea myself. Would not a blade that's hard all the way through be better or does that mean it becomes brittle? And how do you get that layering exactly right?