Heat Treat Question...

Surthriver

Surthriver

Member
I've been using old, used circular saw blades to make my knives because it helps me to get the mechanical skill and experience without having to buy and possibly screw up good steel.
I know a lot of saw blades were made out of L6. I have no idea if mine are or not.

Anyway, my question is: Should I heat treat knives I make from these saw blades? It would seem to me that blades with carbide teeth would not be as good a steel and would not be heat treated because its relying on the carbide to do the cutting but blades that have their teeth cut right into the metal should be better??? Would they already be hard enough as long as I don't take out the temper by overheating on the grinder?
 
The only thing that you can do is to heat treat one and see how it goes but only if you are doing your own heat treating. The best bet is that they will not because saw blades with carbide teeth are usually of low carbon steel but the only way to really know is to try to harden one an see if it will break when struck with a hammer. Then you will have to experiment with the tempering with another one.

Doug
 
Those old saw blades do tend to make decent blades - NOT the carbide tipped type, but regular saw blades. I just checked one and it's about 40Rc as it sits. The blade WILL need heat treating after profiling to a blade. I'd think starting as if it were L6 would be a good place to start. Quench, then check to see if a file skates - it a file won't cut at all, then it should be over 63 Rc and ready for tempering. This is NOT for carbide tipped saw blades. AND - the 40Rc hardness is ONLY for the single sample I tested - but I "assume" (remember about "assuming") most will be similar.

Ken H>
 
Ok thanks for the help. I've got a whole stack of saw blades to work with and I'll try out both of yall's suggestions. Thanks again!
 
The non-tipped blades will make a good knife. How do you cut them out to shape? Grinder? saw? If you've got a forge you might anneal them and make them a good bit easier to grind, drill, etc. Then do a quench in..... depending on what you've got, regular quench oil? Even Canola oil works pretty good.

Having fun - Ken H>
 
KenH said:
The non-tipped blades will make a good knife. How do you cut them out to shape? Grinder? saw? If you've got a forge you might anneal them and make them a good bit easier to grind, drill, etc. Then do a quench in..... depending on what you've got, regular quench oil? Even Canola oil works pretty good.

Having fun - Ken H>
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I’ve been using a 4 ½ inch cut-off wheel on a angle grinder to profile my blades down to rough shape and then I work them down closer to the line on my 4x46 grinder. I don’t have a forge, but I do have a charcoal grill lol. In fact that’s what I’ve been using a lot to heat treat my knives….Pretty primitive to say in the least. => Its obviously not digitally controlled so all I can do is heat to non-magnetic then quench. I’ve been using a goop mixture to quench in: used motor oil, bar and chain oil, olive oil, and canola oil all mixed together.
 
Dude... good steel is cheap compared to the labor you're going to put into it. The vast majority of my knives use about $2 in steel each, even with shipping figured in. There is no good reason to skimp on steel. If you're going to heat-treat it yourself with your setup, get some 1084 from Aldo or MKS. Canola oil by itself is fine for quenching 1084, the additives are not helping and may be detrimental.
 
GHEzell said:
Dude... good steel is cheap compared to the labor you're going to put into it. The vast majority of my knives use about $2 in steel each, even with shipping figured in. There is no good reason to skimp on steel. If you're going to heat-treat it yourself with your setup, get some 1084 from Aldo or MKS. Canola oil by itself is fine for quenching 1084, the additives are not helping and may be detrimental.
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I agree with George.

At least get yourself a few feet of known steel to give your self a baseline for the performance of your saw blades after you heat treat them.
 
Run them by a tool and die shop and give the guys a few bucks to test the hardness on them. Take the soft ones and frisbee them into the neighbors yard.
 
GHEzell said:
Dude... good steel is cheap compared to the labor you're going to put into it. The vast majority of my knives use about $2 in steel each, even with shipping figured in. There is no good reason to skimp on steel. If you're going to heat-treat it yourself with your setup, get some 1084 from Aldo or MKS. Canola oil by itself is fine for quenching 1084, the additives are not helping and may be detrimental.
Click to expand...

How does 1084 compare to 1095? I'm familiar with 1095 but not 1084....
 
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1084 is considered the best all around blade steel for a newbie - temperature control isn't so critical while heat treating as for other metals. 1095 is a good bit more temperature critical, so is normally considered more of an "expert" steel. The saw blades that are hard will make good knives - just test and see if the file "skates". If you were closer, I'd say bring some blades over and we'll do a Rc test to see where they're at. Every blade you do doesn't need to be tested, just a few until you've got a method for heat treating, then it will be fairly repeatable from that point.

If your labor is $10/hr, then buy good steel. BUT - if you labor is like I am - really CHEAP!! then perhaps hold off on buying good steel until you've got more experience. I've made several knives I didn't have $5 of "real" cost in, that was mostly sanding belts 'n sandpaper. Steel and handle material I picked up around the shop. With more experience, now I tend to buy most of my steel so I know exactly what I've got. Once this electric oven gets here I should have good control of my heat treating. I've been using a gas forge with muffle pipe and a temperature probe inserted inside pipe for temperature control.

Ken H>

Ken H>
 
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