
Dewalt has launched new 5-flute 82° countersink drill bits for use in metal, wood, and plastic materials.
Dewalt says the 5-flute design avoids excessive vibration and provides for smooth drilling.
They all have round shanks and are said to be suitable for handheld and stationary drills.
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There will be a 5pc set, and the drill bits will also be available individually.
Sizes include 1/4″. 3/8″, 1/2″, 5/8″, and 3/4″. Here are the model numbers:
- 1/4″: DWAMDB16CS
- 3/8″: DWAMDB24CS
- 1/2″: DWAMDB32CS
- 5/8″: DWAMDB40CS
- 3/4″: DWAMDB48CS
- 5pc set with all sizes: DWAMDB5SETCS
At the time of this posting, Amazon has the 5pc set at $25, and Acme Tools at $50. To give you an idea of individual bit pricing, Amazon has the 1/2″ bit for $13, and Acme Tools has it for $17.
COO: Made in China
Discussion
It’s a little surprising that Dewalt would launch countersink drill bits, but I’ve seen similar from construction tool brands before – my first multi-flute countersink was Bosch-branded.
Maybe there’s a deeper takeaway here, but I’m not seeing it.
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I’m not much a fan of multi-flute countersinks like this; I prefer the zero-flute designs. Maybe it’s poor technique, but they always seem to chatter on me, leaving poor surfaces. I’ve seen others complain about similar issues before, but I’ve always assumed they could have poor drilling technique too.



Alexk
I bought a very cheap set from Harbor Freight years ago. Think they were less than $5. They are adequate for wood.
HC
ditto
Jim Szabo
5 flutes TiN Coated are good on some metal, the Zero Fluts have their place but a squirt of oil, or lubr (even canning wax stick). But the trick is easy on the throttle, as these are Chinese made doesn’t vote me well.. I found 1/4″ hex versions from Ryobi in 1/2, and 3/4″ @ 82 degree in HIGH speed steel pretty good for less then $25 @ Home Depot. The trick with the hex drive bits is the extensions adaptability, 1/4″ impact driver. I use mine several times a week as cheater chamfer tools in a machine shop. If your looking for 90 degree version (metric c’sinks) Shaviv (Vargus) has the Zero flutes, and 3 flute in 90degrees
fred
I too find chatter to be an issue with this design. While my go to countersinks are zero-flute (with and without pilots) from Weldon – Amazon sell this set of zero flute that they say are their choice for a fraction of the cost:
https://www.amazon.com/OCGIG-Countersink-Chamfer-Titanium-Deburring/dp/B07P543FGB
Stuart
I have a deep aversion to no-name power tool accessories. I try to stick with name brands – usually from industrial suppliers for things like this, as the quality tends to be consistent. With no-name Amazon brands, you never know what you’re getting.
fred
I certainly agree – and don’t expect Weldon quality at 1/4 the price. But a 4-piece set at under $17 still might be worth a try for use on wood or plastic. When I buy anything from Amazon (even name-brand stuff) – I always try it out immediately – and return it if I’m not satisfied. Returns can be an extra hassle but in my neck of the woods – a return is usually to a nearby Whole Foods store – so the hassle is minimal. Meanwhile my recommendation for a known-quality set is still Weldon at around $73:
https://www.amazon.com/Weldon-99046-94-W-SET-Flute-Countersink-Deburring/dp/B00Q5INRUQ
JohnBCS
Yeesh. I paid $33 for that weldon set back in 2007 according to my amazon purchase history. Amazing countersinks though and still holding up today.
MM
Agreed. In my experience running a machine shop the difference in performance between name brand and generic tooling is massive. I avoid mystery-name countersinks, drill bits, end mills, plain milling cutters, etc.
I prefer single or zero-flute countersinks. I think the reason why the multi-flute ones are so common at hardware & big box stores stores is because they are robust and difficult to damage. Single-flute and zero-flute countersinks are much more easily dulled by careless use.
KokoTheTalkingApe
I was going to say something like that. The angle at the edge of a zero-flute must be pretty darn shallow (also it changes depending on the size of the hole, also the shearing action can switch from up to down). That edge must be pretty easy to damage.
I love mine but I haven’t used them enough to wear them out at all.
UberChemist
I keep both on hand, but the zero-flutes get the lion’s share of the work. The multi-flutes do chatter like crazy (even on a drill press), but they do bore out much faster. For larger screw sizes, I’ll get close with the multi-flute then finish with the zero-flute. I’ll burn up a zero-flute trying to hog out a big hole by itself. I’m mostly cutting 316SS, I think most materials are more forgiving. I’ve been eyeballing a milling machine for years, and I think that’s the proper machine for multi-flute countersinks. I just don’t have room
KokoTheTalkingApe
Just so people know, these are 90 deg countersinks, which are good for chamfering holes but won’t fit standard screw heads perfectly. Also the description says they aren’t for use in hand drills: “This bits should use the bench drill , it is easy to shake and it will affect the chamfering effect if you use the hand drill.”
But they’re high-speed steel (4241, an inexpensive “entry-level” HSS, I’m reading) and they’re cheap.
And I love that design. I’m going to buy a few of the Weldons you suggest.
fred
Keo is another brand with which I’ve had good experience.
MM
Keo is excellent, they were my go-to for center drills and zero-flute countersinks.
Jim Szabo
Keo are still made here in the States, they are made by Arch Tools out of Michigan. Arch has bought up some small companies with solid names, and brands and help keep these names revenant, and obtainable
MFC
The chatter happens because we push too unevenly when it’s by hand with a drill. Then, like a rut in a road, the up/down pressure of the bit cutting into the metal or wood gets worse and worse and ruts out even larger cuts followed by hills from less pressure.
A drill press takes out the unevenness unless you are just cranking on the handle excessively or the bit is worn. So, I’d say stick with zero flute for handheld use since the unevenness happens across a much larger swath of material and can be smoothed out more easily.
David A.
I never knew they made single flute countersinks! I have always used the multi-flute ones! I am not a wood craftsman but occasionally build a project where these provide a nice touch. I have never experienced the vibration mentioned but again I don’t use all types of wood but usually pine in my projects.
Grady
I was al over this until I saw the coo. I’ve used multi-lute countersinks when I was a machinist. Yes, they do take careful application.
Jager
I’d imagine it’s from the same supplier SB&D uses for their irwin countersink bits and it was just a cheap way to add to the yellow offerings by having some of them come out of the factory in yellow packaging.
Matt_T
They sure look like rebranded Irwin Hansens right down to the undercut on the body. Irwin 1877793 appears to be the same set.
Will
No 90° for metric? Seems the only time I have issues with chatter, is if the rpm is too high or there isn’t sufficient pressure applied. Really prefer single flute when precision is needed.
Matt_T
Doubt there’d be much interest in Dewalt branded metric. Most people buying box store cutting tools won’t even know metric uses a different angle.
fred
Or that oval head machine screws may fit better with a 100deg. countersunk hole.
We also used 60deg countersinks for chamfering the edges of holes for bolt clearance
S
I’ve been using large-step step bits for my countersinking needs because every one of these multi-flute metal countersinks chatters too much.
fred
For chamfering large holes – my choice is the 1-1/4-inch diameter Beall single flute countersink #THCS – $34.50 at Lee Valley. I think Lee Valley actually acquired Beall some years ago.
NoahG
I swore off big box countersinks years ago, they barely work in wood let alone metals. Irwin’s in particular are the worst, and these look like rebranded Irwin’s. I really like the Keo stuff McMaster sends. My local place carries countersinks from Alfa tool which are decent as well. I’ve built up a solid inventory of single, triple and six flute countersinks since I work with wood, acrylic, aluminum and steel.
EBT
I swore off 1/4″ hex shank type bits after I snapped an Irwin 1″ wood auger drill bill (for running electrical lines through 2x4s). It was old lumber ofcourse, but it caught the auger and the Dewalt 1/2″ drill snapped the shank off.
And THAT is why you use that side handle on a 1/2″ drill… (without snapping my wrist).