Anyone tried spiral flute countersink?

[Roger Feeley]

I’ve always struggled with chattering. It’s always been good enough but I never got a truly smooth surface. Then I stumbled across spiral flute countersinks that: a. Promise a perfect surface and b. Promise to empty my wallet.

https://www.mcmaster.com/countersinks/smooth-finish-high-speed-steel-countersinks-for-screws/

https://www.guhring.com/BrowseProducts/Products/Countersinks

thoughts?

[Bill Dufour]

I prefer a piloted countersink in a countersink cage. Micro depth adjustment to 1/1000" with a hand drill. Just make sure the angle is correct. Many aircraft countersinks are 100 degrees, not 90.
I would guess those shown are 100 degree. They will work good enough in wood for rough work not visable. If they will show buy a 90 degree threaded bit to match. 1/4 thread mount is the standard cage size. there is also a 3/8 size cage.
Bill D.

[Jamie Buxton]

For wood I use a single-flute countersink which I got from McMaster-Carr. It is way way better than the usual big-box countersink, which I think is intended for metal.

[George Liverman]

I picked up this KEO set on Amazon and have been very happy with them.

https://smile.amazon.com/gp/product/B00947BXJW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

[Bruce Page]

I have used the spiral flute countersinks in metal working but I never cared for them.
Chatter can usually be controlled with RPM. Slow is good.

[Wes Grass]

The 'zero' flute type are great, and they make them with pilots as well. But I wouldn't use them on steel. The cutting edge is frail and easily chipped, or just dulled from overheating. Nothing better on aluminum, and probably the only thing that cuts gummy plastics cleanly.

The single flute are tougher. Anything with multiple flutes is prone to chatter, unless they space the flutes unevenly, which I can't recall ever seeing in a c'sink.

[Carl Beckett]

I picked up this KEO set on Amazon and have been very happy with them.

https://smile.amazon.com/gp/product/B00947BXJW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I use this style as well. Leftover from my machine shop days. Buy a good quality and they cut quite nice (and do not have the chatter issue you are finding)

For screws I mostly use the tapered pilot hole/counterbore set from woodriver.

But to your question: I would think the spiral cutting nature of the ones you posted would help with chatter. But I have no experience and instead use these other styles to avoid the problem to start with.

[Alan Lightstone]

I use the Amana Tool countersinks. Just switched to them a month ago - I used to use the ones from Lee Valley.

Expensive, but work very well. They are 82 degrees, with a nice depth stop on bearings that is pretty good at not marring the surface.

https://www.amanatool.com/nsearch?q=countersink+adjustable+depth+stop

[Mike Kees]

I use the Amana Tool countersinks. Just switched to them a month ago - I used to use the ones from Lee Valley.

Expensive, but work very well. They are 82 degrees, with a nice depth stop on bearings that is pretty good at not marring the surface.

https://www.amanatool.com/nsearch?q=countersink+adjustable+depth+stop
Thanks for this post. This is exactly what I need. I have also used the KEO style ones above and found them to be excellent in both wood/manmade products and mild steel, with no chatter.