Best steel choice for big Bainite Bowie?

T

the possum

Joined
Jul 31, 2002
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Well, I'm still trying to sort out what's going on with my Bowie knife. I'm in touch with the heat treater, and it may turn out that I ground it from crappy steel, possibly the end of a mill batch or something. If we can figure out what went wrong, great. But, I'm already preparing for the worst- starting over.

So, if I have to do it all over again, what steel would be best for a large Bowie knife, made into bainite? I used 5160 this time, but from research here see that maybe O-1 has possibilities as well. What do you guys think? This knife will be light and quick for its size; I'm thinking about making use of fullers and hollows added into a convex main grind, even though they won't look right on a Bowie.
 
Quick, let me throw my vote in before Kevin Cashen gets here! L6, of course!
 
The blade steels that are suitable for austempering to get bainite are 5160, O1, L6. Toughest is L6, best edge retention is O1. Kevin C is experimenting with a O1/L6 damascus, that in bainite would be super !
 
Wow. I didn't think the replies would be unanimous! So I should focus on L-6. Now for the big question... where can I get it in flat barstock? I need 1/4" thick by at least 2" wide, or maybe even 2 1/4" wide, by 24" long. I haven't searched yet, but have always heard it's hard to get in sizes that stock removal guys use.
 
L6.

Don't know about sizes, not a maker.

L6 goes by "Champaloy" at Crucible, one potential source.

Can also suggest you register at www.swordforum.com and ask those guys... Howard Clark uses this stuff in large sizes, others too probably.

http://www.crucibleservice.com/products.cfm#

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Originally posted by mete
Kevin C is experimenting with a O1/L6 damascus, that in bainite would be super !
Click to expand...
And it would look great also. Cashen has gotten my attention with this mix... for sure. Although I haven't heard that he's done this in bainite... just wondering out loud if the TTT curves are close enough that he could use one "split the difference" heat treat and get them both into bainite.
 
Rob, they are quite close, both have about a 10 second nose and 450-500F quench temp for bainite.
 
Everything that I've heard about Admiral's L6 is that it ISN'T. I have not used it personally but many reputable smiths say that it behaves nothing like Crucible's. I have also read many reports of it failing while being forged. I have not been able to locate L6 in flat stock anywhere, have read that it hasn't been produced as such for many years. You might check with some of the smiths and see if they will sell you some stock that has been forged down to the thickness and width you desire.

Mete and others in the know, how much of a difference is there in toughness between O1 and L6 in the bainite state? If it is not radical, I'd say go with O1. You can buy it just about anywhere.

2 cents from the guy with no sense, stevo
 
I think Kevin mentioned this company, although I do not recall if he purchased his L6 from them.

www.carpenterdirect.com

In looking at their web site, it appears that they have L6 and small and very larges sizes, flat and round. I have never used their services, but would be interested to know if anyone else has. Is there a minimum order dollar or steel wise?
 
Hey Possum,

You finally getting around to makin the coon killer (racoon for you sensitive types)

I was reading some old posts to see a picture of peternaps hunting sword and read your old post. Too funny!!:D
 
Originally posted by stevomiller
Mete and others in the know, how much of a difference is there in toughness between O1 and L6 in the bainite state? If it is not radical, I'd say go with O1. You can buy it just about anywhere.
Click to expand...
Great question. The toughness data that get's published would be at a given hardness in martensitic structure. In this martensitic state, Crucible says:

For L6:
Code: 
Temper
°F   °C    HRC  ft-lbs  
-----------------------
As quenched 63-65 - 
300  150  63-65  15  
400  205  60-62  43  
500  260  58-60  38  
600  315  56-58  68  
700  370  53-55   -
For O1:
Code: 
Temper
°F   °C    HRC  ft-lbs  
-----------------------
AQ 63-65 – – 
300 150   63-65  14  
350 175   62-64  28  
400 205   61-63  30  
450 230   60-62  –  
500 260   58-60  30  
600 315   55-57  32  
700 370   51-53  –  
800 425   48-50  –  
900 480   43-45  –  
1000 540  39-41  –
So picking Rc56-58 to emphasize L6's "sweet spot", well, at least in the size of sample that Crucible tested in the Charpy machine:
O1 is in the 30-32 ft-lb range.
L6 can hit the 68 ft-lb range.

So L6 is ~ 2x tougher at it's sweet spot in martensite.

But in Bainite?... :confused:

(amazing how those toughness vs. hardness curves aren't always real clean... numerous have dips and humps, notably A2 and L6)
 
Thanks for the help, fellas. I tried that carpenter site, and the thinnest stock they list is 1/2 inch thick. I didn't want to do that much grinding!:) But, I will still give them a call and see if they have any smaller stuff they don't list on their website. I've got a few smiths in mind who supply steel; will have to call them & see if I can find any. If not, well then I guess I'm stuck with 5160 again.

Gouge-
Yeah. I "finished" this Bowie a few months ago. (actually I never really polished it very well since it's just a "beater", and there may be some problems with the steel or heat treat) I've only got a few critters with it so far, as things are kinda slow this time of year. If you're interested, very soon I'm gonna collect a lot of my favorite stories and post them on another board. I could give you the link if you care to read the uncensored versions.
 
I have a 50 Ft lb. charpy tester, I will soon have a more accurate 60 Ft lb, and have tested both O1 and L6 pieces in blade cross sections. Just plain oil quenched, no fancy heat treating tricks, with both tempered to around 58HRC. Despite what many prevailing opnions say about O1 brittleness, it actaully did better than some other steels that I thought could beat it. The O1 has absorbed around 21 foot pounds in 1/8" thick blade shape cross section, and 8 foot pounds in 1/8" flats notched. This is nice but then there is L6...
The L6 in the same shapes and sizes, in unnotched tests, maxed out the tester, even with multiple hits! It required around 21 Ft lbs to break the notched bar. Weakened by the notch, the L6 behaved like unnotched O1, but unnotched it was unbreakable even in a fully quenched tempered martensite condition. Marquenched, it would max out a much larger tester, this is one of the reasons why I have not felt the need to work with bainite all that much, it just seems to be overkill for a problem that I have not experienced.
 
For those who don't know it's the nickel in the L6 that makes it tough.......Kevin, having seen the E-bay photos of the impact tester you will have some work to do. We want it all cleaned and polished !
 
Originally posted by mete
For those who don't know it's the nickel in the L6 that makes it tough.......Kevin, having seen the E-bay photos of the impact tester you will have some work to do. We want it all cleaned and polished !
Click to expand...

What color do you think I should paint it? Hot pink or a pastel blue;). What I am looking forward to the most is the heavy frame work, my home made model had vibration to contend with. I always get consistant results but that rattle makes me nervous. All I want to hear on impact is the sound of the test piece popping.

For the price, I think I can afford to do some maintenance.
 
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