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  • Cutting thick aluminum stock

    I have some thick stock of aluminum that I recieved from a friend in a small CNC Mfg company. Its basically 4"x4"x4" and 4"x4"x2" blocks. Today I tried to slice a 1"X1"x4" piece off one of the blocks with my jet 4x6 band saw. I have had wonderful cuts and performance with this little band saw with steel. I assumed it would cut equally well on aluminum. I started without changing the blade speed and even used some WD40 for lub, but it seemed to take forever to progress into the metal. I then changed the speed to the fastest setting and found the cutting was somewhat faster only by adding down pressure to the saw. After I progressed about 3/4 way thru the cut it was apparant that the cut was creeping out and making a terrable belly in the cut to the extent that I had to readjust the clamp on the parent block. I did cut this material in the horizontal position of the block assuming that the most teeth in the cut was best, but maybe I should have cut it vertically and been more patient!!!!!. I made the poor asumption that the saw would cut aluminum faster that steel..... What do I know.
    Is there a methodology for cutting thick aluminum, and can it be done accurately with this tool? I am also using a high quality, fairly new Bimetal variable pitch blade(Lenox). I also did not notice any material buildup on the teeth of the blade that would reduce its effectiveness.
    Skipd1

  • #2
    A coarse tooth blade will cut much better. What happens if your using a fine tooth blade on a huge chunk of aluminum is the teeth fill up before they exit the part. WD40 is for rockets... use dishsoap with some water on ally.

    John
    My Web Site

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    • #3
      Originally posted by BigJohnT View Post
      A coarse tooth blade will cut much better. What happens if your using a fine tooth blade on a huge chunk of aluminum is the teeth fill up before they exit the part. WD40 is for rockets... use dishsoap with some water on ally.

      John
      Never heard of using that cutting solution for Aluminum. I would be using Kerosene. You need a blade with coarse teeth for thick stock, especially Aluminum. Trying to re-saw that block with what you've got is false economy.

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      • #4
        Originally posted by skipd1 View Post
        I have some thick stock of aluminum that I recieved from a friend in a small CNC Mfg company. Its basically 4"x4"x4" and 4"x4"x2" blocks. Today I tried to slice a 1"X1"x4" piece off one of the blocks with my jet 4x6 band saw. I have had wonderful cuts and performance with this little band saw with steel. I assumed it would cut equally well on aluminum. I started without changing the blade speed and even used some WD40 for lub, but it seemed to take forever to progress into the metal. I then changed the speed to the fastest setting and found the cutting was somewhat faster only by adding down pressure to the saw. After I progressed about 3/4 way thru the cut it was apparant that the cut was creeping out and making a terrable belly in the cut to the extent that I had to readjust the clamp on the parent block. I did cut this material in the horizontal position of the block assuming that the most teeth in the cut was best, but maybe I should have cut it vertically and been more patient!!!!!. I made the poor asumption that the saw would cut aluminum faster that steel..... What do I know.
        Is there a methodology for cutting thick aluminum, and can it be done accurately with this tool? I am also using a high quality, fairly new Bimetal variable pitch blade(Lenox). I also did not notice any material buildup on the teeth of the blade that would reduce its effectiveness.
        Skipd1

        First, at what speed are you running your saw? Second, what is the TPI of the blade you used in cutting off the 1”x1”x4” piece from the aluminum stock? The positioning of the material when cutting may vary because of the no. of teeth made in a cut, remember the three tooth rule.
        Last edited by bosox; 10-05-2012, 05:19 PM.
        if you can't take criticism, do the right thing.

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        • #5
          Originally posted by Rosco-P View Post
          Never heard of using that cutting solution for Aluminum. I would be using Kerosene. You need a blade with coarse teeth for thick stock, especially Aluminum. Trying to re-saw that block with what you've got is false economy.
          Yea, an old machinist taught me that trick when tapping aluminum and you didn't have any proper tap lube. Works for sawing too... I'd never use a flammable liquid around an open frame motor commonly found on cheap bandsaws.

          John
          My Web Site

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          • #6
            cut thick AL on the 4x6 often. I have a 6tpi blade I only use for it.
            If your a brave man and can stand the spray of hot chips, use a 10" tablesaw with a 80 or 100 tooth HF carbide blade. I made a "sled" that the material clamps to, guided in the slot on the table. use it for material too large to fit in the 4x6 horizontal. Thick stock I cut in 2 passes, cut one side, turn over reclamp to the sled, cut the second side. I have cut 2'x3' x3" AL into useable chunks this way! you get real creative when you get a slab of free stuff

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            • #7
              I use a 4/6 carbide tooth blade for thick material and it pulls curls of steel or aluminum off like you never saw before.

              John
              My Web Site

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              • #8
                Ok, this is what you should do. First, in cutting aluminum, you should run the saw at 150-250 sfpm. Now, you said you have two blocks, a 4”x4”x4” and a 4”x4”x2” and you wanted to slice a 1”x1”x4” piece off in any one of the blocks. Regardless in what manner you cut the blocks, either horizontal or vertical,
                a 3-4 variable pitch blade can do the job. But always remember, observe proper blade break-in procedure when you have a new blade. And remember to hold work firmly and accurately by proper alignment of the vice clamps to allow square cuts. Lastly, the quality of the blade can also affect your machine’s cutting performance. I get high quality bi-metal blades from sawblade.com. Call them for blade recommendations regarding your problem.
                if you can't take criticism, do the right thing.

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                • #9
                  There is something wrong with the blade. It must be dull or the set is gone. Even a fine blade will zip through aluminum in a hurry as long as you keep it well lubed with WD-40. It is the best for cutting and machining aluminum and I do a lot of aluminum. You say "even used some WD40 "... Why would you cut metal without a cutting lube? Even on a hack saw it cuts much faster and saves wear on the blade. It's no different from cutting metal in a lathe or mill.

                  There is no speed limit when cutting aluminum. The faster the better as long as it is lubed. Lube prevents chips from sticking in the tooth gullet which will slow down cutting to nearly zero. I don't mean an occasional squirt either, but a continuous drip on the cutting edge. You can cut aluminum just fine on a wood bandsaw and most all woodworking tools work well with aluminum. I use carbide router bits in my mill to mill aluminum.

                  Don't use carbon steel blades (the blue ones). They aren't worth the money. Use bimetal blades and even though they cost twice as much they will last ten times longer.
                  Free software for calculating bolt circles and similar: Click Here

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                  • #10
                    7x2" 14tpi cut dry.





                    Andy

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                    • #11
                      like others have said, change to a coarse blade, 4 or 6 tpi is what i have irrc. with a long section in cut the chips needs somewhere to go...that I'd bet is your problem I don't bother changing speeds, too much a pita and with a coarse blade it's done so fast it wouldn't be worth it.

                      just hold onto the frame when starting it.....you have control the feed until a few teeth are engaged or its going to dig in, break teeth, start to feed crookedly etc
                      in Toronto Ontario - where are you?

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                      • #12
                        I was always of the assumption that a blade that cut a "Belly" in the stock was Dull,, and--One side was duller or wore more than the other. Also slack blade tension produces a "Belly".

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                        • #13
                          I was always of the assumption that a blade that cut a "Belly" in the stock was Dull,, and--One side was duller or wore more than the other. Also slack blade tension produces a "Belly".
                          Agree. The other thing that will cause a cut to veer off is feeding too aggressively, but this is unlikely with a self-feeding horizontal saw (unless you are leaning on it).

                          Also, I don't bother to change blades and use the same one for both steel and aluminum, and always with cutting fluid. The blade has more TPI than most have recommended for Aluminum, but it works fine. I have also used a table saw, but it is a) messier, and b) more nervous-making since the work is not clamped.
                          "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

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                          • #14
                            Place a block of wax or a candle in front of the work so the teeth cut thru the wax first, then into the aluminum. This will provide lubricant and prevent galling while making minimal mess.

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                            • #15
                              Originally posted by mickeyf View Post
                              Also, I don't bother to change blades and use the same one for both steel and aluminum, and always with cutting fluid. The blade has more TPI than most have recommended for Aluminum, but it works fine..
                              point of clarification....I rarely change blades either and use the same blade for 98% of it; the change to a low # of tpi isn't because its AL, its because its a 4" long cut
                              Last edited by Mcgyver; 10-08-2012, 01:02 PM.
                              in Toronto Ontario - where are you?

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