Countersink Bits

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    David B

    Is there a special name for the kind of countersink bits that Paul uses? His appear to be hollow on the inside whereas just about everything I see (on Amazon) are solid bits. Not that there’s anything wrong with them, I just wasn’t sure if there was something unique/special about the ones Paul is using (or if they had a special moniker)?


    Larry Geib

    One thing to be mindful of, especially with hardwoods and hardware, is to match the countersink to the type of screw you use. There are two major standards for the manufacture of flathead screws that are different angles.

    ISO (metric) uses a 90 degree included angle, while UTS (North American) uses an 82 degree angle.There are several other angles as well, but those are the most common for wood screws.

    Using the wrong countersink will tend to either cause pressure on the wood, increasing the likelihood of splitting, Or it can put stress on the screw ( important with soft brass). It can also leave a visible gap at the surface. you can get away with more with softwoods.

    And crosshole bore like Paul uses or single flute sinks cut smoother in most materials than multiple flute cutters. Single flute are cheaper in carbide, if you need to cut metal.


    These are often listed as deburring bits rather than countersink. I have a set from Harbor Freight that worked well, but dulled. I’ve not found an effective way to sharpen them, but surely there must be.


    I came across an old Stanley Countersink on EBay that is meant to be used in a brace. It is conical with a slot that has a sharp edge. I sharpened it an put it into an old Spofford Brace that I had. It is now a dedicated countersink. and cuts cleanly. By counting the turns, I know the countersinks are all the same depth. This is an unsung advantage of going manual versus electric power.

    I also picked up one of those one handed manual countersinks from Veritas. It is a cone with several cutting ridges. You just put it in the hole and rotate back and forth. Great for softwoods and in hard to reach or fragile places.

    Philipp J.

    I believe what you mean is a “Cross-Hole Countersink”, granted i didnt have the chance use them a whole lot but if my boss is to be believed they work better then regular Countersinks.

    Fine Tools from Germany has them for example

    Peter George

    I use one from the hardware store in my wheel brace. Like FrankM, I can count the turns to make the countersinks equal.

    Peter in
    Biggar SK
    "New York is big, but this is Biggar"


    I bought this one recently on Amazon. It cuts much smoother than my regular countersink and doesn’t chatter. It wasn’t cheap but I love it.


    What Larry said was on point.
    I first used a hand countersink bit. They comes in sizes, and the major online vendors will have a set or two.
    Then I found bits that fit in braces. The positive points cited here are real. They also come in sizes. but they are usually found on eBay, so diligent shopping is called for.
    Countersink bits also were made for push drills/screwdrivers. The chucks for these are of different types and sizes: I use a Millers Falls driver, with the “30” code. If the bit has a “30” on it somewhere, on on the case or envelope, it will fit. Adapters are also available used.
    The handy bits are the ones that have a hex base for a hex holder in the driver. Highly interchangeable, including for the most modern screw types.
    Countersink bits come with different numbers of flutes in the bit, from one to many. Obviously more will give you a smoother cut. For depth, the hand bit and brace bits lend themselves to counting the number of turns, but I go slowly in finer work by measuring the cross section of the hole at the surface. Sometimes it’s most accurate by simply stopping and holding the head of the screw to the surface cut in the wood. Just remember it’s easier to take out more wood than put wood back in the place from which it was cut. 😉
    Have fun. They make great collector items, and the all metal stanley line is available new, as at Garrett Wade, but that comes with a price and less hunting.

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