Dustin Stephens
Hello All, I have aquired a 4ft dia. saw mill blade and this thing is a beast!  It seems rather old and I was wondering if anyone knew what metal they used to make these things, roughly?  The wife sees a hunk of metal but I see at least 40 knives[smile]
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jmccustomknives
In my experience a blade that size that has carbide teeth brazed on is going to be L-6 or something similar.  Cut in teeth are generally 1060-70 class steel.  Sounds like a good find.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Dustin Stephens
I dont think it has the brazed teeth but ill have to looks closer, its got an english bull dog painted on one side and silver paint on the back, Ill grind it this weekend to see
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Dustin Stephens
Here it is
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jmccustomknives
That one is a carbide toothed blade.  I love that steel.  It's very forgiving.  Just cut your blanks out and grind them out, don't even bother with forging as it's just a waste of time.  You'll want to anneal if you are going to drill through.  Heat treat is a breeze.  Heat to nonmagnetic, quench in canola.  Temper at 375-400, for a big knife do a soft back draw.  It will be unbreakable.

Just remember, that blade was culled for a reason.  It probably has a crack somewhere so keep an eye out for it.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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NorrinRadd
Nice find!
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Anthony San Miguel
I have a friend who has about a dozen 2 foot circular saw blades that are actually stamped with the alloy. They are D4. I can get some, but I wouldn't know what to do with such a complex alloy.
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Skarzs the Cave Troll
Jay Fisher wrote:
D2 has a lot of carbon. A LOT. This varies somewhat between manufacturers, but know that the extremely high amount of carbon is critical to this steel's very long and proven reputation. Simply put, it has some of the highest carbon content of any steel. Other types of "D" steels have up to 2.25 percent carbon (D3, D4) which is more carbon than cast iron! The king of carbon in high chromium-high carbon tool steels is D7, which has 2.35 percent! D3, D4, D5, and D7 are not used to make knife blades because they are too brittle, and not tough enough to resist fracture in thin cross sectional areas.

Another blade smith, who I have a book written by, is Jim Hrisoulas, and what he said about D2 is that it is an air-hardening steel (though it can be quenched in oil), it tends to be red-hard, that is, it is likely to fracture when forged at lower temperatures (much like L6), and it is not for the beginner forger. But if you're cutting out knives, I think you'd find it a little easier than forging, though some research may have to be done on the heat treatment. (Jim Hrisoulas also says "Tempering: 400F-1000F." Not kidding.)

D2 is often found in jackhammer bits, because it is so wear-resistant and durable, but I have a couple pieces and I'm hesitant to take a whack at them because of their size.

First time I tried to make a layered-steel, I was using pieces of saw blade, and it ended up fracturing not in the welds, but one one end that broke in half. After I found out that what I was using was probably L6, a red-hard type of steel, I know now that it can't be worked below dull orange.
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Greg A
That's pretty good. I've seen a youtube where a guy makes a knife out of a saw. Nice find
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jmccustomknives
That blade probably isn't a true D-4, I'd be scared to use something like that as that alloy would be deadly spinning at those speeds.  That stamp probably means something else.  About the strangest alloy I've run across is some that were a M series, which makes sense as that is a high speed alloy.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Dustin Stephens
Hey James, a feller on another form said that a saw blade that has brazed or inserted teeth is of 4130 low carbon steel?  Any thoughts on that?  4130 I think is low carbon steel with like .3% carbon which means crappy knife??
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jmccustomknives
4130 would be crappy steel.  I've never run across any of it.  Don't know where he got in info either.  Sometimes word of mouth gets spread around and the truth gets left in the dust.  Cut you off a test piece, about 1/4" wide and 5" long.  Heat it to non magnetic and quench in warm oil.  Put it in a vice and hit it with a hammer.  If it breaks easy you've got some good steel.  If it is really hard to break or bends you've probably got 4130 (which I've never seen listed as a saw steel).
I was at a bladesmiths meeting and there was a guy selling large band saw blade as L-6.  I've never seen any company that ever listed L-6 as a band saw material.  It's just a story that got passed around and ended up with a guy who'd probably never tested his steel selling it as something it wasn't.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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jmccustomknives
Oh, those blades can be L-6 but usually vary in alloy content depending on manufacturer.  L-6 is kind of the catch phrase for these steels, they could be 8670 or some other alloy.  They just have to meet the requirements of the tool being made.  4130 is a tough steel, but with out the nickel that is in most of the saw steel used in those blades it would fatigue rapidly and fail. 

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Dustin Stephens
so whats the best way to test it?  My junk yard buddy has one of those light saber haha, spectrometer thingys
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Dustin Stephens
ill give her a whack this weekend.  Hope it breaks because there is potential for alot of knives in that blade
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Dustin Stephens
Ok James, I heated it to non magnetic at work and quenched it in their cutting oil and it took 2 decent whacks to break it, and the grain size was real tight like sand, Is it good?
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jmccustomknives
Sounds like you got it.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Dustin Stephens
Saweet!
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jmccustomknives
Bring your heat down a little on the next one.  I see a little graining on the second.  Use a good broke file as the example of what it should look like.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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jmccustomknives
I should have asked, "what was your procedure for the test?"

1. Normalize - heat the piece to just under non-magnetic and let cool to black.

2.  Bring to nonmagnetic, keeping the heat even.  When the piece reaches non-magnetic bring the heat up just a little and quench in oil.

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Dustin Stephens
I was running my forge at about 15psi, I think for this process she should be around 8 or 9, but Im just learning and really need a thermocoupler and a good meter thatll reach the temps I want
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