Heat treat?

[ranger1]

I have always used SS and have sent it out to be tempered.I am making a blade from an old sawmill blade(blade is about 36"in diamiter.I have no idea what kind of steel it is.
What would be a good way to HT and temper.Or at least a place to start.
Thanks in advance

[combs6136]

most sawmill blades are L6....Great knife steel but rusts easily... I have a five footer that i cut tomahawks or hatchets out of..........carl

[Andrew Garrett]

Not knowing exactly what it is, I'd do it the easy way (pretty much the way I do all my carbon knives).

First: anneal it. The next day or later: Grind out a blade. Heat up a scrap prybar and drop it in the quench pan for a pre heat. keep a magnet next to the forge (or torch as may be your set up) and heat the blade to critical. When it starts getting red, check it to to magnet (make sure the magnet it wired down to something). When it no longer attracts the magnet, edge quench it. (you could repeat this as many as three times if you want)

File test it after it cools enough to touch.

I temper at 450* for an hour. I repeat the temper (after it cools) for anything real thin or a knife I want extra tough. I do only one on most for max edge retention. With an edge or clay quench, it has yet to be a problem.

This process is real basic and works on most of the carbon steels I use. 10XX, Nicholson files, old circular saw blades, etc.

[AwP]

Go with Andy's advice, but let me follow up with this... If it fails the file test, do the same thing again except when the magnet doesn't stick then put it back in a little longer and let it get a little hotter and try again.

[AcridSaint]

Hey Andy, I also have a very strong suspicion that it is L6. You should talk to Tony Kelly about it, he only uses large saw blades out of L6 and he might be able to tell you about it if you can tell him some details about the saw. If you've been to a guild meeting you've probably met him. If not, well he'll probably be at the one next week... or you can just give him a call, I'm sure he'll tell you about his experience with L6 saw blades.

If you're just going to test it, I would not use brine or water, just heat it to non-magnetic and quench in oil. Andy's directions above are pretty fail-safe. Oh, also, I'd temper at 400* for one hour and go up from there, just in case it decides to go soft early, or in case you didn't test your oven and it runs a little hot

[ranger1]

Thanks guys,Cap see you sat.
That is alot of steel just laying around.Time it saw some use.
I've got to get a forge

[IronMonkey]

Don't go to the expense of buying one! Build it! I have pics of mine and can send you info your way about how I did mine. It is a lot of fun to build. A lot of it can be done with scrap, junkyard, ebay finds. I got my squirrel cage blower off of ebay, the digital thermometer, thermocouple etc. Give me a call sometime. I am sending out the camp spears for heat treat tomorrow . So far I am very happy with how they are turning out. Now that I will have a break for a little bit I only have about 11 other knives to hand sand and get ready for heat treat in my forge. Dan