A guy I work with knows I have been making a few knives and he asked if I would like some saw blades. I knew his uncle had a saw sharpening shop and I told him sure I would try one. The next week he brought me four 40" diameter saw blades that were worn enough that his uncle had the guy replace with new ones and gave me these. The teeth that hold the carbide tips were worn away.

What I am wondering is since the saws have carbide teeth if the metal will get hard enough to make a blade that will hold a edge. I cut a 2 x 6 inch strip from one of the blades and heated it to past nonmagnetic and quenched in oil. I then placed it in a vise and snapped it into. It was very brittle and the grain looked very fine in the break i had not tempered it any. I appreciate and feedback and thanks in advanced.

Ronald

I tried to do the same with a piece of a large broken saw blade that required carbide tips to cut.
The steel in the main blade was at mid 40s Rc before and after H.T.

You need to start with a blade that does not use hardened tips.
I acquired a very old 26" mill blade that was made with one uniform steel including tips.
Besides original hardening of the whole blade, it had also some age and work harding.
It makes a pretty good blade.

In my experience anyhow.

Thanks for that information. After seeing the carbide tips I was afraid that was going to be the case.

We have used several of the old very large saw blades with carbide teeth for knives. We haven't noticed any difference between the steel used in these blades and the ones without carbide teeth. Both harden very well and easily temper to 59 RC. I guess it could always very according to the saw blade, with a newer blade being more likely to be made from a steel that isn't great for a knife blade. I would say normalize it, harden and temper a piece just like you would a finished blade and see what happens. When we tested the steel, it performed like L6 in the heat treat.

We were very pleased with the resulting knives and they have held up well. They do rust very quickly, but many people like a knife with a patina on the blade. I recently saw the top knife that was made for a Civil was re enactor and the patina that it now has is gorgeous!

Older tipped style saw blades could very well be made with carbon steel instead of mild.
I was referring to my only two efforts of using larger saw blades.

The failed blades I was trying to use were new stuff from the large cutting equipment used in forest harvesting.

Like everything else, you gotta check to see for sure when harvesting mystery steel.
Higher probability of untipped style being hardenable steel I would think.

That is a beautiful knife. Congrats.

Mathsr,
Thanks for the added information. On the strip that I quenched a file would skate across it and not dig in. I think I'm going to try making a meat cleaver from one first and see how it holds up to the pounding on a cutting board.

I agree with MRK both of those knives are very nice.

"Like everything else, you gotta check to see for sure when harvesting mystery steel.
Higher probability of untipped style being hardenable steel I would think." MRK

I agree completely. Test a piece of steel first before you put a bunch of work in it and find out it won't harden. There is a lot of steel out there to be had, but very little steel that was designed with the idea that it would harden and be wear resistant enough to be a good knife. Key word being "good." I think that most saw blades these days are designed to be tough and not break. There is a lot of potential liability in slinging a large piece of steel around at a very high rpm, so they focus on making it tough. They aren't designed to be wear resistant and hold an edge. They braise carbide tips on them to hold an edge. They must have continued to use the high carbon steel for the blade body even after using carbide tips for a while. Just got to check and get lucky.
Picture of the period blade after 4 or 5 years of camp use...I love that stuff!