S7 Bowie

I have a TTT diagram for type 512 very similar to S7 [type 513], you will have to quench in salt bath at 650F for bainite, and it will only take about 10 minutes !!The curve is strange and they mention that it's hard to get all martensite ,you'll usually have some bainite too !....Air hardening steels will never give you a hamon because it will be martensite all through the blade rather than martensite /pearlite......Jeff, give all you blades a nice 2 hour temper, they'll be very relaxed then.....Fitzo, I guess you could get into a discussion about martensite vs bainite for L6 with Kevin. You can get into a fine line between which is better ,dropping a few points in hardness to get a bit more toughness. The first thing is to look at the TTT curves and see which steels are appropriate for bainite [time].I'll have to look into this question.
 
Thanks, Robert! It was just curiosity, so don't go to too much trouble. Dang, only 10 minutes? I though the bainite transform took hours!

Do you have Ven Der Voort's "Atlas....." to get your TTT diagrams?? Or do you know where I can scrounge actual TTT's? I'm thinking that something that would be way nice to have is a compendium of TTT's and hardening/tempering charts of the common knifesteels for everyone here.

That danged book is so expensive at $215 new that there's no way I can afford it for just 15-20 diagrams. Amazon doesn't have any used, either, so I'm clueless where to look. I emailed Kevin but if you have any insight it would be most appreciated. Thank you, again.
 
Thanks, Roger, they don't have one now but I'll keep an eye open over there. I didn't even think of ebay, so that was a great suggestion..
 
Jeff,

The one thing I would suggest NOT doing is quenching in STILL air. I think I saw that mentioned somewhere within this thread. If with air, give a quench with lots of even air flow. If you can coat it with a protective powder or paint you can quickly oil quench it. I am sure I used Brownell's BPC for coating Mark's big S7.

RL
 
There is one person that immediately comes to mind when talking S7 - Daniel Watson. Despite whatever you might have heard, or how you feel, he's been playing with it for tweny years or so. He's got something going, it wouldn't hurt to ask...

Darryl
 
fitzo said:
Thanks, Robert! It was just curiosity, so don't go to too much trouble. Dang, only 10 minutes? I though the bainite transform took hours!

Do you have Ven Der Voort's "Atlas....." to get your TTT diagrams?? Or do you know where I can scrounge actual TTT's? I'm thinking that something that would be way nice to have is a compendium of TTT's and hardening/tempering charts of the common knifesteels for everyone here.

That danged book is so expensive at $215 new that there's no way I can afford it for just 15-20 diagrams. Amazon doesn't have any used, either, so I'm clueless where to look. I emailed Kevin but if you have any insight it would be most appreciated. Thank you, again.
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I get most of my books at ABE Books. I like older editions and slightly used, beats the price tag on new metallurgical texts :eek:
 
This is a trip; there are no coincidences. I was talking to a customer last night who wants his dagger from S7. He works for an outfit that uses it to make rails for nail guns and he's pretty enthusiastic about its toughness too. I'll try to get enough to make myself something. :) Thanks for all the heat treating info. Jeff please keep us posted on your project! Sounds like fun.
 
Kevin R. Cashen said:
I get most of my books at ABE Books. I like older editions and slightly used, beats the price tag on new metallurgical texts :eek:
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Thanks, Kevin! And thanks for the email! I'll keep looking.
 
I have 'Tool Steels' by Roberts which is , of course great for tool steels but doesn't help with alloy or carbon steels.
 
Joe Szilaski uses S7 quite a bit for axes and hawks. You could try contacting him, as I'm sure he's accumulated a good working knowledge of the steel.
 
Holy Guacamole! You guys have spewed-forth so much info I got no idea what to do next! I unwrapped that steel, and its imprinted with "Timken S7" and some other gobbledygook on the sides, so that pretty much clears up any mystery about its origin. It measures 3" x 18" and mikes at .2609, so a little oversized. Should be fun.

The bainite quench has me intrigued. My only caveat is that my low-temp salt pot is in pieces - unassembled - sitting on my bench. I think I'll do this blade according to the Timken recipe for now.

Roger, Mete, Fitzi... what do you guys think of a possible aluminum-plate quench? I also was entertaining the idea of a possible edge-quench in some heated Junell Quench. Please advise. For some reason, my gut is telling me this may be a good thing, as the oil will quench the edge quicker than the air and that the spine will be hard, but a possible transition line may form? I would still temper for two hours anyway, but the variable hardness of the two areas on the blade would both relax and still make for one tough knife. Any comments on thsi idea would be very welcome.

Roger, correct me if I am wrong, but isnt PBC only good for up to 1500 degrees? I think this S7 needs 1725.
 
Jeff, PBS is good to *supposedly* 1650F. Turco is supposedly more like 1900F, though I don't have a spec sheet.

It sounds like this steel needs a really fast quench to max hardness. While I really like my quench plates (1" thick Al) and an airblast in between the plates, I think the oil may be better for a beast of a blade.
 
Jeff,
I use the aluminum plates on S7 and quench press it foil and all. The blade is ground after heat treat. I also use 1750° and 300° x 2 hrs x 2.
 
Yea, Dan, but you saw it in the etched condition. Thought you might want to see the wood and shiny metal :)
 
Mark Williams said:
He said coonfinger :)
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We need a smilie of rofl :)

Friggin Danbo always got the cool rocker avatars, huh? Good onya, Danbo! Jimmy Page, or Clapton next, okay? :D
 
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