Recovered Saw Blade Steel/ Quench Questions

[Eichler]

Hi Folks,

I got a saw blade the other day to turn into some blades and the saw was marked,

Saw Blade 5NJ
Marvel High Speed Edge
Armstronge - Blum Mfg Co.
Chicago 39, Made in USA

.075" thick - 1.95 mm thick
18-1/2" long
1-5/8" width

I was wondering if anyone happens to have a guess as to what kind of steel this is and how best to heat treat. I am concerned about the quench as the blade is pretty thin. I was planning an oil quench but if anyone has any experience with these kinds of blade I would appreciate hearing it.

Thanks,

Ike

[Ray Rogers]

This is one of the problems that come with trying to use an unknown steel - nobody really 'knows' anything with certainty. Except for a few rare cases, you are money ahead (often, quite a bit of money ahead) buying your blade steels.

That said, I will now 'guess' at some of the information you want. First of all, the majority of carbon steels all heat treat the same way. So, they can be annealed the same way and they can be hardened the same way. This simple formula is not always the optimum way to heat treat a specific steel but then, you don't *know* what steel you have so it's the best you can do and it will give useable results. There are plenty of threads on annealing carbon steels and how to use a magnet to harden carbon steels so I won't reinterate all that here.

That is, it will give good results if what you have is actually a blade steel and I have reason to doubt that it is. You said the blade is marked 'Marvel High Speed Edge' and that's a concern to me. Many saw blades are made of soft, non-hardenable, steels so that they can take the punishment associated with being a saw blade and because it can be cheaper to make them that way. Then they have a hard edge attached to the softer body. If that's how you blade was made, it will be useless as a knife.....