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"Drill Taps" ?

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  • "Drill Taps" ?

    Has anyone tried or is using these? Obviously only for through holes Looks like a potential real time saver if the quality is decent. Or maybe it's just one of those "Well, it seemed like a good idea at the time..."

    Click image for larger version

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    "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

  • #2
    Nope, I am waiting for the drill/tap/center punch combo

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    • #3
      I once had dozens of 10-32's to do, so I bought a drill-tap. It worked great for the couple of holes that I did before I broke it. It was not the drill-tap's fault.

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      • #4
        Originally posted by Bob Engelhardt View Post
        I once had dozens of 10-32's to do, so I bought a drill-tap. It worked great for the couple of holes that I did before I broke it. It was not the drill-tap's fault.
        I worked at a place where we had to hand drill tons of 10-24s. We experimented with the the “draps”. When they worked, they worked well and did save some time.

        You had to be real careful on break through with the drill because it was very easy to break the tap, almost to the point it wasn’t worth using them. On the plus side the drill portion seemed to hold an edge quite a bit longer than a standard drill, especially on stainless.

        You can also put a chamfer on the hole with the same “bit”.

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        • #5
          Originally posted by oxford View Post

          I worked at a place where we had to hand drill tons of 10-24s. We experimented with the the “draps”. When they worked, they worked well and did save some time.

          You had to be real careful on break through with the drill because it was very easy to break the tap, almost to the point it wasn’t worth using them. On the plus side the drill portion seemed to hold an edge quite a bit longer than a standard drill, especially on stainless.

          You can also put a chamfer on the hole with the same “bit”.
          Oh, yeah... super easy to break.

          Bad combo in a way.... you want a higher speed for drilling, but then when it breaks through, you need to slow down right away, or the tap will be right through and breaking before you know it.

          Should have used a 3 speed drill, like my DeWalt, but it was at work, making prototypes, and we did not have one like that.
          4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

          Keep eye on ball.
          Hashim Khan

          Everything not impossible is compulsory

          "There's no pleasing these serpents"......Lewis Carroll

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          • #6
            I always figured that those were best used on things like thin to medium wall tubing. Or similar suitable thickness sheet metal. Sort of like Unibits.

            On thicker stuff all the woes you folks are describing would easily come to pass. No time or room to slow the speed down so the tap grabs hard. Or worse, the thread starts to engage and pull the "drap" into the work before the drill point has cleared. That's going to be a grab and snap that happens with a snap of the fingers.
            Chilliwack BC, Canada

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            • #7
              Originally posted by BCRider View Post
              I always figured that those were best used on things like thin to medium wall tubing. Or similar suitable thickness sheet metal. Sort of like Unibits.

              On thicker stuff all the woes you folks are describing would easily come to pass. No time or room to slow the speed down so the tap grabs hard. Or worse, the thread starts to engage and pull the "drap" into the work before the drill point has cleared. That's going to be a grab and snap that happens with a snap of the fingers.
              Thickness of work does not matter (unless you figure it might just strip out). It's the distance from the drill part to the tap part..... and the length from the tap to the chucking area, OR the place (look at those taps) where the diameter increases..
              4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

              Keep eye on ball.
              Hashim Khan

              Everything not impossible is compulsory

              "There's no pleasing these serpents"......Lewis Carroll

              Comment


              • #8
                I think the thinner material, the better the chance you have of the tap surviving.

                Again, I only tried them in a hand drill scenario. Besides drill speed on breakthrough, the down pressure on break through is also a problem and not as easily controlled as when drilling in a machine.

                These would probably work very well if you set them up in a tapping head.

                Comment


                • #9
                  Always wanted to try some, but obviously not enough to shell out $20 for some lol. I'd think you'd want the material thickness to be thinner than the drill section so you'd be done drilling (and could reduce speed and feed pressure accordingly) before you start tapping, no?. Of course that's just wild speculation from seeing a few pictures of them on the internet..... I think they'd be great in thin plate work around 0.1" ish.
                  Last edited by Dan Dubeau; 01-18-2022, 03:17 PM.

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                  • #10
                    The thickness of material could matter, you want the drill all the way through before the tap engages since the feedrate of the tap is substantially faster than drilling feedrates.

                    I have some, never tried them, probably came with a bunch of stuff in an auction purchase. I think in the CNC mill they might be okay with the tool held in tension compression tapping holder. The holder with compress under drilling pressure, then let in extend during tapping and tap unscrewing.

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                    • #11
                      Originally posted by Dan Dubeau View Post
                      I'd think you'd want the material thickness to be thinner than the drill section so you'd be done drilling (and could reduce speed and feed pressure accordingly) before you start tapping, no?.
                      Yes that is correct, they only have a “maximum” material thickness you can use them on, you want to be done drilling before the tap engages.

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                      • #12
                        Well, sure.... less than max thickness, of course.

                        But, 16 ga, 1/8", 3/16" no big difference for the sizes we used..
                        4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

                        Keep eye on ball.
                        Hashim Khan

                        Everything not impossible is compulsory

                        "There's no pleasing these serpents"......Lewis Carroll

                        Comment


                        • #13
                          My most recent Milwaukee impact driver has "Self-Tapping Screw Mode" which drills at full speed & slows down for the screwing. It would probably work pretty well with a drap.

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                          • #14
                            Originally posted by Bob Engelhardt View Post
                            My most recent Milwaukee impact driver has "Self-Tapping Screw Mode" which drills at full speed & slows down for the screwing. It would probably work pretty well with a drap.
                            The speed is only part of the problem, a lot of it is the “mechanics” of the operations.

                            Anyone who has spent time drilling holes in metal with a hand drill and tapping holes with a hand drill knows it’s 2 different ways of holding the drill, muscles used, and body position.

                            The real key to success if using these in a hand drill is controlling the break through.

                            Comment


                            • #15
                              Absolutely correct!
                              4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

                              Keep eye on ball.
                              Hashim Khan

                              Everything not impossible is compulsory

                              "There's no pleasing these serpents"......Lewis Carroll

                              Comment

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