Testing the metal of a saw blade

S

Sprayman

Joined
Nov 15, 2014
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257
Greetings:

These days I mostly order new steel to make my knives, but I'm still making knives out of recycled saw blades occasionally; I like the "up-cycling" process, and I like to practice on steel that's disposable, for when (not "if") I have to scrap it. A couple of the knives have come out nice and hold an edge well, and a few have been garbage. My question is, do you know a way to test the steel from the saw blade before shaping it, to know if it's good enough quality? I want to keep making knives like this, but I don't want my efforts to go to waste.

Thanks
 
You can always cut off a few small pieces and do test heat treats on them..See if they harden correctly and with what quench and temps..If they have carbide teeth don't waste your time though..
 
S.Alexander said:
Interesting. They say fully hardened, but what kind of steel is it? HSS, 4140, 1045?
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Probably something along those lines - I would guess a bit more carbon (maybe 1060-ish). Either way, not ideal for a cutting knife, as Kentucky said. I'm simply making the case that it is not mild steel.
 
"Fully hardened" does not mean Rc60+. A fully hardened saw blade may only be Rc 45. "Fully hardened" merely means that the steel is hardened to its fullest practical degree. 1030 steel can be hardened , just not enough to make a good knife.
 
Stacy E. Apelt - Bladesmith said:
"Fully hardened" does not mean Rc60+. A fully hardened saw blade may only be Rc 45. "Fully hardened" merely means that the steel is hardened to its fullest practical degree. 1030 steel can be hardened , just not enough to make a good knife.
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Exactly what I was getting at Stacy.

Patrick, I don't think anybody was calling modern saw blade steel junk, or mild steel. It's just not suitable for knives. Maybe it's OK for throwing knives, but edge holding isn't necessary for a thrower.
 
When I first started making, I was using mostly Sterratt power hacksaw blades and they made good knives. I did use some thick old round sawmill blade for a usable Ulu that made an excellent blade. That knife went to a taxidermist.

For the working of the hard saw blades I set my shop up for it.

The Ulu was about 1/4" thick and used up a 10" grinding wheel. It was hard stuff but mirror polished like a '57 Buick bumper.

No joke, I was selling a lot of knives then and they were selling for $250-$500. Yes, folks understood what steel it was and that was over 25 years ago.

The only thing I could find to mirror polish that hard of steel was diamond compound.
 
S.Alexander said:
Exactly what I was getting at Stacy.

Patrick, I don't think anybody was calling modern saw blade steel junk, or mild steel. It's just not suitable for knives. Maybe it's OK for throwing knives, but edge holding isn't necessary for a thrower.
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The unmerited blanket statements such as "It's just not suitable for knives" are precisely what I'm trying to dispel. Let's not confuse probability with certainty. We don't know if it is or isn't suitable for knives. We have solid reason to believe it isn't mild steel. At best, it is something like 8670 (which would make a good cutting knife or a great chopper). At worst, it is something like 1030 as Stacy mentions. Only a chemical analysis can tell us exactly what it is and exactly what it is good for. Obviously in 99.9% of cases, an analysis is a waste of time/money with the availability of known steel.
 
I totally agree with Patrick that a analysis test is the only way to know.

My point to the new and inexperienced member is that if the likelihood is 99.9% a wast of time and money, just save yourself the time and money and use a known steel.

Lets put that into real numbers:
You place a bet with me for $50 ( the price of a test). I will toss 1000 pennies in the air and if they all land on heads, I give you $50. IF even one is tails, I win. Would any sane person take that bet?
 
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