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  • Drill bits

    Some time ago I bought a set of Dewalt pilot point drill bits. I have found that its not a good idea to drill a pilot hole for a larger bit as the tip of the bigger bit is easily broken off.

    Recently Ive had a couple of jobs to do that for some reason consumed several bits in the process. Job one, drilled holes for self tapping bolts in a flatbed trailer deck. First drilled large hole in aluminum(for bolt to pass thru) then drill smaller hole in steel I beam crossmember(for self tapping portion). Putting in about a dozen bolts, I managed to bend the larger bit and bend or break off three of the smaller ones. This was all done with a half inch B&D drill. These bits seem to "catch" badly just when the hole is almost complete.

    Today with a near new(19 holes) bit(same size as the small ones above, 17/64) I broke one off in aluminum. Im frustrated beyond belief as its about a 60 mile round trip to buy new bits.

    Did I end up with crappy tools with a good name on them or am I doing something wrong? What brand bits are you professionals using? Do you guys use them by the bucketfuls too???
    Who do you call when the lawmakers ignore the law?

    Miller AC/DC Thunderbolt 225
    Miller 180 w/Autoset
    Old cutting torch on LPG

  • #2
    Those dewalt pilot point bits are trash. Same thing here. The dewalt bits without a pilot are a lot better.

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    • #3
      I usually get my bits from McMaster-Carr. Just get the regular black oxide jobber bits. Any supply house should have them such as Fastenal, etc.

      http://www.mcmaster.com/#standard-drill-bits/=oufuag

      I always drill pilot holes for any job. You really need to brace yourself when using a hand drill to keep it straight when it grabs. Also it needs to be straight the whole time you are drilling. A lot of it is technique. I don't know how many times I see someone using one hand or going crooked while drilling.
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      • #4
        Some suggestions:

        Stay away from imported, mass market drill bits. You know, the kind you buy at the Depot. Buy USA made drills from McMaster-Carr, ENCO, MSC etc.

        For your kind of work, I might suggest that you also stay away from the "split point" drills which can be very aggressive, particularly if you've drilled a pilot hole. Use the standard point drills.

        Also, consider using some sort of cutting fluid if possible, particularly for aluminum which can be quite "grabby" when drilled with hand-held equipment.

        Be aware that all drill bits become very aggressive as they break through the bottom of the drilled hole. You can usually feel this as it starts to happen and you need to ease off on the applied force.

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        • #5
          When drilling a pilot hole, don't make it any larger than the web thickness of the larger drill.
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          • #6
            Agreed. The bits you buy from the fastenal work great with cutting fluid. I use brake fluid. It washes with water. But thats me. The rapid tap oil works great
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            • #7
              When you sharpen your bits for this type of work keep the rake to a minimum. It will cut slower but will grab less. Don't push your drill though let it cut its way though and as stated, ease up when your close to dropping though.---Meltedmetal

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              • #8
                This happens a lot when drilling bolts when safety wiring bolts. I have found that if you don't tighten the bit down so that it may slip at the point of break through you can save a few bits... That may not work as well for the bigger stuff.
                MillerMatic 211 Auto-set w/MVP
                Just For Home Projects.

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                • #9
                  Thanks for all the replies. I do let up at the end of the hole, but with this particular job it didnt seem to matter. I will be investing in some other bits. Many thanks for the brand names. One thing I liked about these Dewalts is the shank is not round, very easy to keep tight in the chuck.
                  Who do you call when the lawmakers ignore the law?

                  Miller AC/DC Thunderbolt 225
                  Miller 180 w/Autoset
                  Old cutting torch on LPG

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                  • #10
                    I use Irwin high speed bits. There the cheapest but work the best for me in alum and steel. We get them at a old local lumber yard there silver colored. I've try all the high dollar ones not no more. They resharpen good too. One of the few cheap products that work.
                    Last edited by Kpack; 10-10-2013, 07:03 PM.

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                    • #11
                      I really like Vermont American bits. They cut very fast and hold an edge well.

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                      • #12
                        Drill bits

                        I use Walter SST bits they are a bit pricey but when drilling lots of holes with a hand drill on site I want them to be good and cut fast but HANG ON!!!

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                        • #13
                          Those trailer decks can be a PITA! They are often high tensile steel. I ended up using the gold coated bits from McMaster Carr as well. I think I used 7/32.......anyways.....with a smaller bit keep your speed up.......don't stop on the way through.....they will snap right off.......
                          Originally posted by Kpack View Post
                          I use Irwin high speed bits. There the cheapest but work the best for me in alum and steel. We get them at a old local lumber yard there silver colored. I've try all the high dollar ones not no more. They resharpen good too. One of the few cheap products that work.

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