Truck springs (put on your reading glasses -- lots of numbers)

[tallwingedgoat]

A while ago Bill said he took a few khukruis to be lab tested and found that they had unusaully high silicon for 5160. Bill then asked if this was caused by the forging process and whether silicon was a good thing.

I talked to some ABS mastersmiths and did a little research. Here's what I found:

It's not possible for silicon to be added in appreciable amounts during forging. Silicon molecules are too big to move through the steel matrix very well.

The steel Bill had was most likely 9260 or 6150, not 5160. It would help if I knew the exact chemical composition from the lab. But basically, the 3 steels are similiar except that 5160 has no silicon, 6150 has .35% silicon and .15% vanadium added. And 9260 has 2.0% silicon.

6150 and 9260 can make stronger blades than 5160 if heat treat is optimal. Silicon is a good thing as it is a deoxidizer and reduces inclusions. Vanadium is great at getting fine grain structure. Thus both elements make the blade stronger in this case.

6150 is sometimes used in leaf springs.

9260 is not used for leaf springs but is often (not always) used as coil springs for pre-1978 GM cars and trucks.

As a side note, on those same GM cars and trucks, the axle shafts are made of 1050 steel. Same steel used for railway tracks -- which in turn was recycled into khukuris in WII.

[This message has been edited by tallwingedgoat (edited 14 July 1999).]

 

[Bill Martino]

I do know that the kamis will grab up truck springs just as fast as any. Could be that's what they had used.

Actually, the fellow who had a couple or three khukuris tested was a customer from Chicago and not me. He visited in Reno and showed me the results when he was here -- promised to send a copy and never did.

Many thanks for the info, goat. I can always learn even at my age.

I used to test airplanes made entirely of aluminum -- and didn't know anything about aluminum. Now I test knives and don't know anything about steel. At least I am consistent.

Uncle Bill



[This message has been edited by Bill Martino (edited 14 July 1999).]

 

[Ivy Mike]

The idea of testing a material without knowing its physical properties can be applied to many of life's mysteries. For example, I do not know the specific gravities nor boiling points of any number of alcohols. However, there is beer that needs to be tested, and I do what I can.

Obligatory knife comment: wish I had a Maccha.

 

[ghostsix]

Chuck Yeager or his wingman Bud Anderson do not know or care a heck of a lot about Bernoullie`s principal.Money is what makes airplanes fly.I`ll leave the details of 5160 to Cliff.I`ll see them in a few days.Same old war stories at the Acey Deucesy Club.I never tire of them.

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[Bill Martino]

I guess it all boils down to the end result -- that's what really counts.

Uncle Bill

 

[Yvsa]

:
What's kind of interesting to me in all of this is the heat treating all comes out well. There may not be enough difference in the materials to affect that. It may also be like the "Magic Stone." It doesn't pay to underestimate the so called "primitive" and "bacwards" people,as I have so many times seen them called. Most of the time thier so called "superstions" about metal and wood working among others have been proven to have merit.
Proper heat treating is an art when it is done the way the Kamis do it.
Especially the zone hardening kind.
One thing the early Europeans had going for them here was thier knowledge of thier native plants and listening to the native cultures here about thier knowledge.
The plants here managed to add many things to the pharmaecolgy.(sp) (to lazy to look it up.

As Uncle Bill has stated so many times and even has the pics of the Kami that is still working out of his g'g'g'g'grandfathers shop. When knowledge gets passed down for hundreds of years there has to be some kind of feeling or knowledge about the material. Perhaps the old Kami that licked the Kuhkuri blade knew something that had been passed down in his famiy.
I have some "Old Hickory" knives that have a odor to me when they are wet and a couple of them will add a certain taste to some foods.


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>>>>---¥vsa---->®
The civilized man sleeps behind locked doors in the city while the naked savage sleeps (with a knife) in a open hut in the jungle.

 

[tallwingedgoat]

I'm not worried about Bill's khukuris, because obvious blade flaws will be caught before they leave the shop. I'm sure that in a life time of smithing blades, the kamis could tell if he's working with a different steel. For example, 6150 will feel like a much thicker piece of 5160 under the hammer.

It's impossible to tell the type of steel on sight. But it does make a difference in the heat treat. A smith I know recently was heat treating what he thought was 5160. After he did everythings right, he still couldn't get it to harden right. From it's look after quench, he figured it wasn't 5160. The blade was then retreated like a 6150, and presto, perfect blade.

Right on regarding traditional techniques ahving their place. I just recently heard a tale about the importance of chrome plating and piss. No one knew why it worked so much better for a long time. Until they figured out the phosphrous was responsible.

[This message has been edited by tallwingedgoat (edited 16 July 1999).]

 

[Bill Martino]

Goat, keep posting. I am still not too old to learn.

Uncle Bill