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Saw Blade Steel

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  • Saw Blade Steel

    I friend in Ely Minnesota gave me a dozen old rusty saw mill blades about 3 foot in diameter.
    She has a second hand shop and got the saw blades as a part of a trade.
    There are lots of saw mills in the Ely area because timbering is the main occupation. (except for mining)
    In any case I cut out a couple of blanks from one of the blades with my plasma cutter and started making some knives.






    As you can see, I have one just about finished and have just started grinding on the other blank.
    The one with a paracord wraped handle is very hard and I had to heat the handle to red to drill a hole.
    I have not heat treated the blade and it seems hard enough to take and hold an edge.

    Here is the question-----
    What sort of steel was used in saw mill blades that were made 20-40 years ago?
    The almost finished knife polished very well after grinding down to 440 grit.
    Can I expect this steel to rust easily?
    If so how would you protect the blade?
    So far I have waxed the polished blade but would like to have a better solution.
    I don't want to blue it or Parkerize it.
    Bill
    Last edited by Seastar; 10-03-2013, 06:09 PM.
    I cut it off twice and it's still too short!

  • #2
    From what i know they were just high carbon steel, what percentage i dont know, i dont know if they practiced microalloying then either
    Mark

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    • #3
      Maybe L6. Clean it to the max, wipe on some phos. acid(it makes it blue black---like gun cold blue) and call it a day. The higher polish the more corrosion resistant.

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      • #4
        Good looking knives!!

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        • #5
          The good saw blades are in the high speed steel range. In fact, cut one up and make some cutoff tools.
          Free software for calculating bolt circles and similar: Click Here

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          • #6
            I don't think they are anywhere near HSS but could be OTL. I bore the eyes for saws by the hundred, yearly. They are high in chrome and high in moly but the exact plate recipe is secret...I have asked and the manufacturer has declined to share their formula. They will work harden and I'll surmise that is why you had trouble drilling your saw plate. I bore them with a carbide inserted boring bar and drill them with solid carbide spade drills. I have drilled them with HSS bits but have used cutting oil and kept the feed constant, chips moving..don't linger.

            Stuart

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            • #7
              Before you put a lot of work into them you might want To do some heat treat testing. The sheet stock that a company I used to work for sold was usually just AR235-285 which won't hold an Edge very long. They also used some C1045-1060 or could be something else entirely. They would punch cut the gullets and seats for the carbides that would get brazed on later. Now I think they laser cut the blanks. This was in Northern CA in 1990ish when they still had a little bit of logging industry. I doubt any of the Mills have survived. This applied to circular saw blades. The big bandsaw blades I believe were high carbon up ton60 feet in circumference, about 10" wide and teeth on both sides. Those things are monsters and would cut through 3+ feet of Redwood faster than you would believe.

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              • #8
                Based on what the good saws are like now I would think HSS is a low quality saw today. There are new ones that are hard to sharpen even with CBN grinding wheels. My wife is in the Industrial abrasives business and has been selling grinding wheels for around 15 years. She is the general manager of a small company and knows her wheels. I'm not talking about carbide blades either. She recommended a customer try very soft aluminum oxide wheels and it worked well. Aluminum oxide is essentialy ruby crystals and the soft wheels shed dulled grit quickly. While the wheels are expensive because of fast wear the new blades don't need sharpening often.

                I have a lot of old industrial blades from years ago and I have used them to make tooling. They are in the same class as HSS as far as lathe tools go.
                Last edited by Evan; 10-04-2013, 11:53 AM.
                Free software for calculating bolt circles and similar: Click Here

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                • #9
                  Double post
                  Sorry!
                  Last edited by Seastar; 10-04-2013, 12:10 PM.
                  I cut it off twice and it's still too short!

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                  • #10
                    When I drilled two holes in the finished knife the steel work hardened about 1/3 of the way through and ruined the drill bit.
                    I heated the spot to red and drilled it hot.
                    That worked.
                    What sort of steel work hardens like that?
                    I think I will cut a coupon and see how it heat treats.
                    air, oil, water or what?
                    Any other tests that might help identify the steel?
                    By the way, none of these are carbide teeth blades, much too old.
                    Bill
                    Last edited by Seastar; 10-04-2013, 12:12 PM.
                    I cut it off twice and it's still too short!

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                    • #11
                      Sounds like Stellite to me which definitely puts it in the HSS range with lots of cobalt.
                      Free software for calculating bolt circles and similar: Click Here

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                      • #12
                        Saws can be tipped with Stellite but the saw plate is only steel...these are two different things. A saw plate is the body of the saw which can be tipped with many different things as well as have simple swaged teeth. There would be no reason to make the saw plate from HSS...plus a simple saw would cost a bazillion dollars..yikes!

                        Stuart

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                        • #13
                          They look good.
                          if you can't take criticism, do the right thing.

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                          • #14
                            Try this:

                            http://www.youtube.com/watch?v=Yq2FwCn3qFA

                            Steve

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                            • #15
                              Saws can be tipped with Stellite but the saw plate is only steel..
                              They are now but Stellite was developed sometime before the 50's. I know because I used to buy stellite valves for racing cars. These are supposed to be very old blades. I suspect they are all Stellite based on the description. There aren't many saw blades now that cannot be drilled. Back then, it obviously was the case.
                              Free software for calculating bolt circles and similar: Click Here

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