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  1. #1
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    circular saw blades ??

    guys/gals :

    Can I harden circular saw blade steel ?? I just got some real nice material.

  2. #2
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    Re: circular saw blades ??

    Check out IR Bailey. That's what he uses. He'll tell you how to harden it too. It might even be in one of his posts.
    Whoever dies with the most tools wins.......Now accepting donations.
    I buy old folding and fixed blade knives of all kinds. Especially Case. PM Me.

  3. #3
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    Re: circular saw blades ??

    I do indeed use a bit of saw blade
    I currently have three different types of blade on the go, one 7/32" thick, one 1/8", and one 4mm. Each of these needs a little bit different heat treat.
    As I don't know the exact type of steel, I have to do some testing when I get a new batch of blades to determine the correct time/temperature for them. This takes a bit of time, but once you've established the correct way to do it, a very good blade can be made.
    Heres how I do it;
    First I cut a blank out. This is then heated until its no longer magnetic, and left in the forge to cool as slowly as possible. This is to anneal the steel in order to make it nice and soft to work with.
    I then grind a blade, leaving the edge about 1-1.5mm thick.
    I then heat the blade to non-magnetic again, and let it cool to room temperature in still air. This is normalising, and sorts out any overheating that took place during the grinding. Its also a good time to stamp my name into the blade.
    The blade is then heated to non-magnetic again, and quenched in warm oil. I heat my oil by sticking a piece of red hot round bar into it. The oil I use is old motor oil, which I picked up from a garage I was working at. I believe it also contains anti-freeze, screen wash, and petrol The fumes from it will probably cause me a slow and painful death, but hey!- it works so I don't care!!
    Once the blade is hard i.e a file won't touch it, heat it in the oven at 200 c
    for one hour. Finish grinding the blade, and sharpen it.
    Do some cutting with it, and try flexing the edge on a rod of about 1/4". If it chips out, its too hard and needs putting back in the oven for another 1/2 hour and trying again. If it bends its too soft and the time needs to be reduced. Once the time/temperature is right, the edge should bend when placed against the rod and then spring back into place.
    Its all about doing a little experimentation.
    Hope this all makes sense to you! PM me if you have any questions.

    Ian

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    Re: circular saw blades ??

    excellent answer as always Ian
    i was given some saw blades by robtatto before he left for the usa
    he said to treat the steel as if it were D2
    ive yet to use and try these blades
    VEGETARIAN . is a old indian word for poor hunter

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    Re: circular saw blades ??

    I've got a big stock of blades I've acquired, and this is a great lesson on how to play nicely (ie. properly) with them! Thanks!

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    Re: circular saw blades ??

    That is mostly what I use, except what I use is concrete diamond blades of the 14" variety. Most of the ones I get are 8670m and the other ones I do as Mr. Baily said.

    SRF

  7. #7
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    Re: circular saw blades ??

    Quote Originally Posted by razor blunt View Post
    excellent answer as always Ian
    i was given some saw blades by robtatto before he left for the usa
    he said to treat the steel as if it were D2
    ive yet to use and try these blades
    I've never used D2, but I have "played around" with some old planer blades which I believe are sometimes made from D2. (?)
    Going by this, I can safely say saw blades are much easier to work!
    I've not noticed too much difference in blades, but for instance the 1/8" blades I'm using polish better than the others, the 7/32" blade needs a double temper, and the 4mm blade seems to be more resistant to rust than the others. If I had cash to spare (dream on!) I'd love to have them tested to see what the compositions are.
    One things for sure, they do make a good blade. I'm an electrician and spend a lot of time stripping steel wire armoured cable. When I used to use an Opinel, I would get through one every 12-18 months due to sharpening it away to nothing. Saw blade knives hold up far better and I've not worn one out yet. They also withstand being hit on the spine with a hammer when I'm too lazy to get my cutters!!
    And of course, they can mostly be picked up for free. Why buy steel when you don't have to?
    I'd recommend them to anyone wanting to make a start in knifemaking, as you can make a few mistakes as you learn and not be out of pocket

    Ian

  8. #8
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    Re: circular saw blades ??

    ThankYou everybody for your replies and information. Much apreciated !

  9. #9
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    Re: circular saw blades ??

    Well Let Me Tell You !

    I had one heck of a time hardening these blades this weekend. I just couldn't get them to harden ! So, after getting my forge fired up REAL HOT, and testing some metal I finnally got 2 too harden. Out of 5 blades, I was only "allowed" to harden 2. I guess the steel Gods trying to teach me this weekend. This is some tough, tough, tough material. I read somewhere that "treat it like L6 steel. I guess I have a lot to learn.

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    Re: circular saw blades ??

    Sorry to hear of your mixed success. Heat treat can certainly be the most frustrating or rewarding part of knife making.

    I've had good luck with circular saw blades before, especially on kitchen knives. Currently most of the family has my saw blade knives in their blocks.

    I always found that they benefited from a long soak time. The steel also seems to be mildly more stain resistant than 1095 or L6 in use.

    As a side note, though you already have some, if you cruise the flea markets older blades can be found, which often are out of a plain carbon steel and more predictable in heat treating.

    Good luck
    James W. Hartman Custom Knives


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  11. #11
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    Re: circular saw blades ??

    Are you talking about the garden variety saw blades for a regular 7.5 inch circular saw for carpentry?

  12. #12
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    Re: circular saw blades ??

    Some people, (most probably), use them. I've never tried one, my blades are 10-18", and pretty thick compared to them... I should buy a micrometer one day.....

  13. #13
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    Re: circular saw blades ??

    It sounds a bit like circular saw blades from the US differ from European blades somewhat. I've never had any problem with heat treat before. My biggest blade is 36" x 7/32", very old, and needs to be held above its critical temperature for a bit longer than my smaller ones but thats about the only real difference during the quench. My smaller blades are 500mm x 4mm, modern, and German made. I have noticed a higher degree of corrosion resistance with the newer steel, but heat treat is still relatively easy.
    I recently asked Wayne Goddard about the likelyhood of most saw blades being L6, and he said in most cases they are made from a different alloy.
    I certainly think that my old, big blade is a far simpler steel than the modern ones. I think the only thing lacking in saw blade steel is the ability to tell someone exactly what type of steel you use, but if it works, it doesn't really matter does it?

    Ian

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    Re: circular saw blades ??

    I heat treat my saw blade steel with my oxy rig. Bring it up til demagnitized ( I edge heat only) keep it that color for about 15 seconds after demagnitized state, then bloop in oil. Since using this method have not had any not harden. Did you normalize first? I noticed a while back this really made a difference with this steel in how hard it gets. Then I temper in my trusty toaster oven 400 deg. F for 30 minutes.

  15. #15
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    Re: circular saw blades ??

    Good Morning Guys:

    Well, I think I discovered my problem. But before I begin, I must say, everyday I am out in the shop I learn something. I the past the only way I was able to harden my blades was with a BIG brake drum forge. Open fire type, forced air from the bottom from my compressor. Quite a nice setup. I have the air line on a regulator so I can control air velocity. I was burning oak. I had a hot fire going. So I thought. What I noticed was that I could not get even heat distribution. I had to keep moving the blade for uniform color/heat. I did manage to harden two blades. BUT, the file still bites every so often. A few weeks ago I built a gas forge here at work. Went and got some propane. Fired it up two days ago. Proceeded the process again. Normalize, allow to cool, then harden, then temper. In my gas forge, I received WAY BETTER heat flow and distribution. The blank heated up evenly. Normalized, allowed her to cool down. Put her back in forge, and heated it back up. Again, even distibution. Once I acheived the proper point of temp., I quenched in some old heated gear oil. She hardend perfectly !! File just skated right across the spine. So I think my problem was I was not getting them hot enough.

    Thanks for all the advice. BTW, these are 10 inch saw blades. Went home that night and tested the blade. WOW ! I post up some pics real soon.

 

 

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