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Hole saw ID? What are they really intended for?

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  • Hole saw ID? What are they really intended for?

    Moved from another location.....

    I have a number of hole saw-shaped objects in the "doubtful useage" category. When I have attempted to use them they have not worked. They are evidently made of HSS, they have very aggressive large teeth with significant gullets, the gullets are 8 to 12 mm deep, the teeth are about 3mm thick.. They almost look like annular cutters.... almost. They have screw-on arbors, and pilots.

    They appear to have good backing off, they seem sharp, and the edges ought to cut, but they have not. It seems to take a lot more pressure to get them to cut. I'm beginning to think they are a fancy wood hole saw. I picked up various sizes at different times, so not some custom thing.

    Here are the culprits. Not the best pic, but these either are hole saws for metal, or ?????

    The solid pilot arbors came on some of the saws. The one with a drill in it just happens to fit, so it got put with these.

    2730

    Keep eye on ball.
    Hashim Khan

    Everything not impossible is compulsory

  • #2
    They are for cutting aluminum.
    12" x 35" Logan 2557V lathe
    Index "Super 55" mill
    18" Vectrax vertical bandsaw
    7" x 10" Vectrax mitering bandsaw
    24" State disc sander

    Comment


    • #3
      Originally posted by ezduzit View Post
      They are for cutting aluminum.
      They are quite reasonably sharp, the edges are backed off, and they wouldn't cut aluminum without (my guess) a 5 HP machine and me standing on the quill to force it down. That might have worked.. Couldn't try that, so I drilled out to 1" plus and then bored. Aluminum was probably 7075



      Aluminum specifically? As in, no other metal?

      The gullets tend agree with that. But I have used very similar cutters quite successfully to cut holes in 12 ga steel for electric boxes and cabinets.



      2730

      Keep eye on ball.
      Hashim Khan

      Everything not impossible is compulsory

      Comment


      • #4
        Maybe for plaster, drywall, masonite, and plywood?
        http://pauleschoen.com/pix/PM08_P76_P54.png
        Paul , P S Technology, Inc. and MrTibbs
        USA Maryland 21030

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        • #5
          Originally posted by PStechPaul View Post
          Maybe for plaster, drywall, masonite, and plywood?
          I'm thinking that the standard carpentry holesaw does that. In fact, I have drilled through plaster and lath with standard "hardened tooth" holesaws. Yes, it dulled the saws, making 8 holes took 2 saws.

          It would dull the HSS ones just as fast, you'd want carbide.

          Carbide cuts concrete and is not dull after a bit of that.... cut an 8" slot in a floor once when the plywood sagged during cutting. Saw was fine after.
          2730

          Keep eye on ball.
          Hashim Khan

          Everything not impossible is compulsory

          Comment


          • #6
            Try slowing them down. Most people run hole saws much too fast. With those you need a lot of coolant.

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            • #7
              Originally posted by Rustybolt View Post
              Try slowing them down. Most people run hole saws much too fast. With those you need a lot of coolant.
              Heck, I was running them slow, using them to try to cut the aluminum in backgear, which is maybe 40 rpm to 100 rpm, depending on pulley choice. I always run them slow, in a hand drill, or a machine. I secided that was best long ago when running them in battery drills. They'll try to break your wrist, but they do cut well that way.

              Holesaw was held in chuck in tailstock, moving the saw in with the ram. Quite a bit of force did not do much. Edges are sharp

              Mebbe it was because the aluminum was likely 7075? That's fairly hard stuff, as well as strong. They just would not cut well. Woodworking type did not cut much better, but they also clogged instantly.

              "A lot of coolant"? I do not have ANY coolant. I was going to put flood on the machine, but this fine batch of folks told me that it would be more trouble than it was worth, and they were generally correct, I think.

              2730

              Keep eye on ball.
              Hashim Khan

              Everything not impossible is compulsory

              Comment


              • #8
                Originally posted by J Tiers View Post

                Heck, I was running them slow, using them to try to cut the aluminum in backgear, which is maybe 40 rpm to 100 rpm, depending on pulley choice. I always run them slow, in a hand drill, or a machine. I secided that was best long ago when running them in battery drills. They'll try to break your wrist, but they do cut well that way.

                Holesaw was held in chuck in tailstock, moving the saw in with the ram. Quite a bit of force did not do much. Edges are sharp

                Mebbe it was because the aluminum was likely 7075? That's fairly hard stuff, as well as strong. They just would not cut well. Woodworking type did not cut much better, but they also clogged instantly.

                "A lot of coolant"? I do not have ANY coolant. I was going to put flood on the machine, but this fine batch of folks told me that it would be more trouble than it was worth, and they were generally correct, I think.

                40 R's is about right.

                JL.......

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                • #9
                  Originally posted by J Tiers View Post
                  ..."A lot of coolant"? I do not have ANY coolant...
                  Use WD-40 on aluminum.
                  12" x 35" Logan 2557V lathe
                  Index "Super 55" mill
                  18" Vectrax vertical bandsaw
                  7" x 10" Vectrax mitering bandsaw
                  24" State disc sander

                  Comment


                  • #10
                    I did a lot of sawing in construction lumber for piping. Had a set of bimetal saws. They looked like a piece of 2" deep bandsaw that was formed and welded. It took a powerful plumbers angle drill to drive them. Fast forward 25 yrs. Construction trades use mostly battery powered drills because of OSHA regulations and fines. Seems they can always find a defective power cord. They have developed a carbide tipped low effort hole saw. It only has a few teeth with large gullets and cuts faster than the old type. I also have a small wood sawmill. It has a 22" circular blade with only 5 teeth. Only requires 15 hp gasoline motor to run it. Saws thousands of board feet between sharpenings.

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                    • #11
                      Originally posted by ezduzit View Post

                      Use WD-40 on aluminum.
                      That's generally what I do, but in this case, IIRC it did nothing much. It was a while ago that I last tried using one. I assumed you meant flood by saying "a lot of coolant".

                      You said "for aluminum"..... did you mean they are optimized specifically for aluminum and are not suitable for anything else? Looks a bit like it, with the big gullets, but evidently not too great on 7075.
                      2730

                      Keep eye on ball.
                      Hashim Khan

                      Everything not impossible is compulsory

                      Comment


                      • #12
                        I believe they are for aluminum.
                        12" x 35" Logan 2557V lathe
                        Index "Super 55" mill
                        18" Vectrax vertical bandsaw
                        7" x 10" Vectrax mitering bandsaw
                        24" State disc sander

                        Comment


                        • #13
                          Originally posted by ezduzit View Post
                          I believe they are for aluminum.
                          That also makes sense because with "McBoeing-Boeing" plant here there is a fair bit of aluminum machining in various local subs, and appropriate tooling is all over.

                          Still surprised they seemed sharp and backed-off correctly but would not cut the 7075.
                          2730

                          Keep eye on ball.
                          Hashim Khan

                          Everything not impossible is compulsory

                          Comment


                          • #14
                            They certainly look the deal. I would have thought those would do quite well but look like they would need some significant horsepower as there is a lot of surface contact in the workpiece.

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                            • #15
                              Originally posted by plunger View Post
                              They certainly look the deal. I would have thought those would do quite well but look like they would need some significant horsepower as there is a lot of surface contact in the workpiece.
                              You'd think so, yet the arbors are for a hand held drill.....
                              2730

                              Keep eye on ball.
                              Hashim Khan

                              Everything not impossible is compulsory

                              Comment

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