Springs, files, and drill bits are all good sources of high carbon steel for knives. I have a Finnish knife made from a piece high carbon steel sandwiched between low carbon. Can’t remember the name of that process. You can see the layers due to the chromium content of the high carbon steel.

Unfortunately for him, a GM coil spring isn't "high carbon" steel. And, to show the innovation power at GM, they've been using the exact same alloy for coil springs since the 1970s. Ford uses a stronger alloy that allows the same performance with less weight.

 

I have a Finnish knife made from a piece high carbon steel sandwiched between low carbon. Can’t remember the name of that process.

The word you may be looking for is "San Mai". But many things were made using wrought/bloom iron and a steel cutting edge back in the day. Steel was a harder to make thing than iron so the steel was forge welded only in a cutting edge, like an ax.
https://en.wikipedia.org/wiki/San_mai
https://en.wikipedia.org/wiki/Bloomery

 

Springs, files, and drill bits are all good sources of high carbon steel for knives. I have a Finnish knife made from a piece high carbon steel sandwiched between low carbon. Can’t remember the name of that process. You can see the layers due to the chromium content of the high carbon steel.

Senpai

 

I'm sure the Swedes had a different name for it but 55 years later I can't remember it. Here it is! A Frosts Mora Laminated Steel sheath knife. Still very sharp after 55 years of beating around. I was thinking it was Finnish but it's Swedish. My dad brought it back to me from one of his business trips to Finland, Sweden, and Norway back in the 60s.

You can make out the separation line near the point and belly of the blade. Very evident IRL. Gold inlay on the sheath's hunting scene embossing. Brass and leather bolsters with oiled birchwood handle.

From: What Is San Mai Steel - This Traditional Japanese Knife Is the Sharpest Of All! - Lafianna.com
"San mai steel originates from Japan. The Japanese terms san mai actually means three parts. And that’s the most accurate description indeed because these blades consist of a center core made using hard steel and two outer layers or edges made with more pliable, milder steel.

So the manufacturing method includes the best of both worlds – hard steel and mild steel. The hard metal in the center makes the sheer edge sharp. Thus, the most suitable for cutting and slicing. On the other hand, the milder version of steel surrounds the core to provide excellent shock resistance while also preventing the pure hard metal from shattering."

Here is my paternal grandfather's IXL dirk from his toolbox. Also very sharp ~100 years later. I did talk to someone on the west coast who does IXL appraisals and repairs about rehandling it but never did as I am very reluctant to let it out of my hands. I love George Worthington I*XL steel. Very hard and durable.

The thread in the sheath is rotting and the belt loop on the back of it is falling off. Leather very dry and brittle after 100+ years.

 

Senpai

I think my spelling is the correct one or at least the one mostly used in knife language.

Senpai = https://en.wikipedia.org/wiki/Senpai_and_kōhai

 

I think my spelling is the correct one or at least the one mostly used in knife language.

Senpai = https://en.wikipedia.org/wiki/Senpai_and_kōhai

@shortbus is the right one, San Mai
@Yaakov is off on a Japanese Anime thought or a dream about a Japanese mentor with "senpai".

Senpai

 

@shortbus is the right one, San Mai

SamR must have me on his ignore list. Yaakov gets a like for his wrong answer and I get ignored.

 

Wasn't going to bring this up but think I should.
When I was still working before retiring I worked with two guys that are well known custom kife builder, have had many of their knives in magazines over the years and won awards for some of their creations.

Andy Shinosky was one of my apprentices for some time and we worked on a couple of designs. I have a few knives he gave me for my help. One of them is one of a kind, a switchblade with 2 different locking mechanisms it was a prototype to work out the lock/opening system. He kind of concentrates on folders.
https://www.arizonacustomknives.com/knives-by-maker/shinosky-andy/
https://www.knifepurveyor.com/shop/andy_shinosky_custom_knife_goldlip_engraved_knife_261/

The other guy was a journeyman like me when I worked with him, Tom Downing. at the time he made fixed blade knives. https://downingknives.com/

 

I think my spelling is the correct one or at least the one mostly used in knife language.

Senpai = https://en.wikipedia.org/wiki/Senpai_and_kōhai

Sorry, I didn’t see your answer before posing mine. Your answer is correct, I mad ea mistake and compounded it by not searching sufficiently to vet it. Thanks for the correction.

 

Just picked these up at a garage sale for $2 each. I can't identify the one on the left but the one on the right is a $70 knife.

 

 

The saga continues! The Benchmade has come home to me yet again. This is its most impressive reappearing act yet. Get this, I lost it in Texas and found it in South Carolina. I came out to SC a couple of days ago to commission the controls on a new packaging line and as I walked past a workbench, there she sits! I asked around about it, just how the hell it got there, someone said that the mechanic who had been here for the past month (also flew in from Houston for this installation, left the day I arrived) had lost a knife and was looking for it. Someone found it and put it on the workbench for him but he had already gone home. So either he straight up stole it from me or (more likely) I left it somewhere and he found it and claimed it, and then he lost it too, and I found it.

View attachment 262472
He completely destroyed the edge and got it covered in epoxy paint, but these things can be fixed. I'm just glad to have it back. This getting too weird...

I only had the Benchmade for a couple of months before I lost it again. Found this morning on the old lawn mower I robbed a spark plug from last year. Not sure why I needed a knife for that; I probably just had it in my hand and set it down to pick up something else.