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Thread: Countersink drill bits

  1. #36
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    Default Re: Countersink drill bits

    Maybe he is talking about the square shanked bits that you use with a brace. As far as I know, they are no longer being made but I could be wrong.

  2. #37
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    Default Re: Countersink drill bits

    Quote Originally Posted by Gordon Bartlett View Post
    What kind of drills were you using as a kid? I have always mostly used regular jobber's-length twist drills. High speed steel with a 118 degree point. These are definitely not the best choice for drilling wood, but it's what I have and, used with care, they get the job done. I haven't noticed any significant change in this type of drill during my lifetime. I'm 66. Maybe if you could describe the kind of drills you are looking for we could help you find them.
    I've ordered two Stanley Screw-Mate countersink bits thanks to Edward P. One #10-1inch and one #10-1-1/4" to screw on my 1/4" ply sides and 3/8" ply bottom. They drill pilot hole, clearance hole and countersink in one shot. I remember using Screw-Mate bits 40 years ago and they worked well. Will see if the ones I ordered fit the bill.

    Other than that, my whole life I've used the standard twist drill bits that come in a set from 1/16" to 1/2" and standard "countersink only" bits. They work for 3 step operations (pilot, clearance, countersink) for occasional projects but too time consuming for plywood boat building using screws. .... I also use the spade bits from 1/4" to 1"+ for general around the house wood drilling. Electricians like the spade bits for drilling holes to run their wires in homes.

    I'll be buying a 5 bit set of straight+countersink drill bits just to have it on hand now that I got interested in that type of bits. Will only buy from a known reputable woodworker tool company and not a cheap set from Amazon. It appears that the recommended Fuller brand only sells tapered + countersink bits. I have not been able to find any Fuller straight + countersink bits.
    Last edited by DayTripper; 06-10-2021 at 02:11 PM.

  3. #38
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    Default Re: Countersink drill bits

    The Fuller countersink will take a straight bit, just doesn't come with one.

  4. #39
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    Default Re: Countersink drill bits

    Quote Originally Posted by bob winter View Post
    The Fuller countersink will take a straight bit, just doesn't come with one.
    Thank you for that info.

  5. #40
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    Default Re: Countersink drill bits

    I have petty much finished up the repairs on my Sea Skiff. I had planned on buying Fullers and got to a point I really needed something now. So I went to Lowers, bought a set of Kobalt bits figuring they would get me going and I would order the Fullers.

    Hundreds of holes in plywood latter I still using them and I am totally surprised and impressed. I broke one of the drill bits and just bought a new set. I had every intention of buying a set of Fullers. Just can't justify it now. These worked much better than any of the cheap ones I have used in the past.
    Jeff
    Kudzu Craft Skin boats
    SoF boat kits, supplies and plans

  6. #41
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    Default Re: Countersink drill bits

    Quote Originally Posted by Kudzu View Post
    I have petty much finished up the repairs on my Sea Skiff. I had planned on buying Fullers and got to a point I really needed something now. So I went to Lowers, bought a set of Kobalt bits figuring they would get me going and I would order the Fullers.

    Hundreds of holes in plywood latter I still using them and I am totally surprised and impressed. I broke one of the drill bits and just bought a new set. I had every intention of buying a set of Fullers. Just can't justify it now. These worked much better than any of the cheap ones I have used in the past.
    Thanks for sharing your experience. I see that Lowes has a 4 bit set with straight bits. Going by what you just said, I might give the straight bit set a try the next time I go to Lowes. And since they are cheap enough, I might give the tapered 3 bit set that you linked to a try also.

    Thanks,
    DayTripper

  7. #42
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    Default Re: Countersink drill bits

    I've come to the conclusion that when it comes to countersink drill bits, there is no one set that fits all. One has to select the screw to be used and then match the countersink drill bit to match the screw, tapered or straight, diameter and length of pilot hole, diameter and length of clearance hole, countersink for flush head or counter-bore for recessed head.

    For screws that are tapered from tip to head, then tapered bit is appropriate. For screws that are pointed with straight sides, then straight drill bit is appropriate.
    Drilling to attach 1/4" or 3/8" thick plywood requires short clearance holes as opposed to attaching 1" thick longitudinals to frames that require 1" long clearance holes.
    So I need to buy the screw to be used first and then buy the countersink drill bit to match the screw.

    Where a countersink with straight bits set to fit all would be handy, is getting a set for the different size star drive screws that are commonly used around the home. For boat building, I think buying individual bits to fit the screws to be used might be the way to go.

    More complicated than I first thought,
    DayTripper

  8. #43
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    Default Re: Countersink drill bits

    Two cordless drills, one set up with a Fuller counterbore and a straight bit the same diameter as the screw shank, the other with a straight bit for the pilot hole.


    That pretty much covers all the applications. You can forget the tapered bits and screw-mates, they're just confusing things.


    Jim

  9. #44
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    Default Re: Countersink drill bits

    Quote Originally Posted by Jim Ledger View Post
    Two cordless drills, one set up with a Fuller counterbore and a straight bit the same diameter as the screw shank, the other with a straight bit for the pilot hole.


    That pretty much covers all the applications. You can forget the tapered bits and screw-mates, they're just confusing things.


    Jim
    Actually he'll need three drills. The last one to drive the screws. I installed many a stair handrail using this system back when. But those drills were all corded. Battery drills were still a vision in the far future. Talk about a tangle of cords!

    Jeff

  10. #45
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    Default Re: Countersink drill bits

    Quote Originally Posted by jpatrick View Post
    Actually he'll need three drills. The last one to drive the screws. I installed many a stair handrail using this system back when. But those drills were all corded. Battery drills were still a vision in the far future. Talk about a tangle of cords!

    Jeff
    I remember those days, Jeff, one of the drill was always my trusty Milwaukee, the one that couldn't be killed and weighed five pounds.

    As the thread was about countersink bits I left out the driving drill, which is sometimes replaced by a brace and straight bit if the screws are large. Every time I put a plank on my boat I have to wait a couple of days for the tendonitis to subside before continuing.

  11. #46
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    Default Re: Countersink drill bits

    Quote Originally Posted by Jim Ledger View Post
    Two cordless drills, one set up with a Fuller counterbore and a straight bit the same diameter as the screw shank, the other with a straight bit for the pilot hole.
    That pretty much covers all the applications. You can forget the tapered bits and screw-mates, they're just confusing things.
    Thanks for your suggestions.

    Regarding screw-mates, I used them to attach the plywood on this Glen L. SK boat that I built about 40 years ago. (That's my father in the boat and my friends to help move the boat out of the garage. I took the picture.) I mounted a chevy 283 cu in motor in that inboard boat but no pictures of the completed boat.

    SK Boat 27b 800ppi.jpg

    Being 40 years ago, I can't remember the steps in building it now except for using burlap bags and boiling water to bend the plywood and that I used screw-mates to drill pilot hole, clearance hole and countersink in one step.

    Yesterday, I received the 1-1/4" x #10 screw-mate that I ordered from ebay. Measuring it, it's perfect to drill the pilot hole, clearance hole and countersink in one step to attach the 3/8" plywood for my upcoming jon boat build.

    I will be buying a straight bit countersink set to have one handy.

    Thanks,
    DayTripper

  12. #47
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    Default Re: Countersink drill bits

    That's a fine looing speedboat you built there, Day. I can see where you might have needed hot burlap bags back by the tumblehome aft, that's quite the bend!

    Good luck with the screwmates, if they worked then they'll do the same now. If you ever want to try something new, though, you know what to get.

    Hey, let's see some photos when you build the boat.

    Cheers

    Jim

  13. #48
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    Default Re: Countersink drill bits

    Quote Originally Posted by Jim Ledger View Post
    That's a fine looing speedboat you built there, Day. I can see where you might have needed hot burlap bags back by the tumblehome aft, that's quite the bend!
    Good luck with the screwmates, if they worked then they'll do the same now. If you ever want to try something new, though, you know what to get.
    Hey, let's see some photos when you build the boat.
    Cheers
    Jim
    Thanks. It will just be a very simple jon boat so not even close to the complex boats that I see posted on this website, but I'll be happy to post some pictures of the build. It depends on when 6hp outboard motors are available again.

    Keep it warm,
    DayTripper

  14. #49
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    Default Re: Countersink drill bits

    Quote Originally Posted by Kudzu View Post
    I have petty much finished up the repairs on my Sea Skiff. I had planned on buying Fullers and got to a point I really needed something now. So I went to Lowers, bought a set of Kobalt bits figuring they would get me going and I would order the Fullers.

    Hundreds of holes in plywood latter I still using them and I am totally surprised and impressed. I broke one of the drill bits and just bought a new set. I had every intention of buying a set of Fullers. Just can't justify it now. These worked much better than any of the cheap ones I have used in the past.
    Can the tapered bits in your Kobalt countersink set be replaced with straight bits? Do the supplied tapered bits have flats on them for the set screw?

  15. #50
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    Default Re: Countersink drill bits

    This cheapy worked quite well until it needed sharpening, which cant be done.

    IMG20210615142409.jpg bit.jpg
    There is nothing quite as permanent as a good temporary repair.

  16. #51
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    Default Re: Countersink drill bits

    I have actually freehand sharpened one of those.It may not have been quite to factory spec,but it allowed me to finish the job that day.

  17. #52
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    Default Re: Countersink drill bits

    I found it hard to keep the point central.
    There is nothing quite as permanent as a good temporary repair.

  18. #53
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    Default Re: Countersink drill bits

    What they all said. Fuller. Only way to go. You can call up, talk to a human and get them in a few days. I don't think their prices are high, either.

    Joe Carpenter

  19. #54
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    Default Re: Countersink drill bits

    Quote Originally Posted by Stiletto View Post
    This cheapy worked quite well until it needed sharpening, which cant be done.

    IMG20210615142409.jpg bit.jpg
    They can be sharpened, this isn't a cheapy, but it has been quickly sharpened several times and works perfectly. The point is not important unless you are working with very small holes. Note the "flat spot" at the edge, this is adjusted as needed depending on the material you are cutting to reduce some of the rake or "hook" (causing grabbing, or too aggressive cutting induced by sharpening)

    58568315-C594-4DC2-B666-79894AEE45CE.jpg

    ED5AA102-8D89-41F4-807E-A43A2FFB36AB.jpg

  20. #55
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    Default Re: Countersink drill bits

    I use fullers as does everyone else In the shop I work at and every other professional shipwright have encountered. The trick is knowing how deep to set the counter sink and how hard you want to run them in. In certain applications you do need multiple drills to properly clear hole but in most applications the taper bits are work great.

  21. #56
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    Default

    For countersinks, about the best around are Weldon™️ so-flute countersinks. Unlike other countersinks, they don't chatter, and they don't create out-of-round countersinks.

    https://heritagecutter.com/BrubakerW...sinks,446.aspx

    A Weldon countersink is basically a conical drill with a hole bored through it at an angle.



    US Patent 2,829,544.

    Buy the original. They make them stock for 60, 82, 90 and 100 degrees. That will pretty much cover any stock fastener you'll likely encounter.

    https://heritagecutter.com/BrubakerW...o.aspx?cid=149
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  22. #57
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    Default Re: Countersink drill bits

    Quote Originally Posted by Canoeyawl View Post
    They can be sharpened, this isn't a cheapy, but it has been quickly sharpened several times and works perfectly.
    You say the point doesn't matter, but I found that sharpening by grinding the flat shifted the centre point of the bit so that it didn't align with the shaft in the chuck and caused a wobble.
    There is nothing quite as permanent as a good temporary repair.

  23. #58
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    Default Re: Countersink drill bits

    Quote Originally Posted by Stiletto View Post
    You say the point doesn't matter, but I found that sharpening by grinding the flat shifted the centre point of the bit so that it didn't align with the shaft in the chuck and caused a wobble.
    I'm not sure I understand that. It is a single flute cutter and only cuts on one side, you could cut the end of that countersink right off and not miss it unless the remaining flat was larger than the hole you are chamfering.

  24. #59
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    Default Re: Countersink drill bits

    When sharpening a single flute bit like that, take care to keep the cutting edge on a radius line. More metal will need removal at the circumference than at the center.

    Jeff
    Attached Images Attached Images

  25. #60
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    Default Re: Countersink drill bits

    Sorry about the double photo post. And they're both sideways! I really tried to fix it. sigh........

    Jeff

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