Countersinks- Single flute/Zero Flute....?

Single flute and the Weldon zero flute ones is what I prefer. Multi-flute C'Sinks have the tendency to chatter regardless what you try to do to remedy the chatter. Generally have to run very slow to keep the chatter out.


+1. All of my counter sinks are single or 0 flute. Run them slow with cutting oil, and be aggressive with the feed.
 
Who does one off CS sharpening for a reasonable price? I've been looking for a good company, not only for countersinks but for
reamers. Is there someone that will sharpen 3 or 4 CS's?
 
What are you gentlemen using that gives the best results?

My experience; First I buy high quality because anything other than this in countersinking (other than soft wood) is throwing good money after after bad ending up with bad results. The zero flute's work well but I tend to restrict them to smaller diameters and non ferrous because they don't stay sharp as long as the single flute's. I have 2-3 M.A. Ford's (carbide) still in the package because I didn't want to get stuck halfway through the job with a dull CS.'s, and that was based on another CS brand. This was a 304 stainless project and after 50+ 1/4" holes using Tapmatic EDGE creame, and still going strong I can't say anything but positive. As Bob already said; Slow speed and heavy feed.
 
Who does one off CS sharpening for a reasonable price? I've been looking for a good company, not only for countersinks but for
reamers. Is there someone that will sharpen 3 or 4 CS's?
I suggest asking your industrial machine tool supplier. Look for tool grinding services. Looking for sharpening services includes too many knife, lawnmower and saw blade sharpening services.

Edit; ....or a quick Google gets you Superior Tool Co. Inc. in Tanawanda, NY. :)
There must be more services closer to you in Connecticut or Massachusetts.
 
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I prefer my weldon zero flute over others. I have both unpiloted and piloted.
I have 4 flute, 1 flute, 3 flut, and if I remember a 6 flute. still prefer the zero, in my opinion usually gives the nicest finish, least chatter, and most controllable depth free hand w/o a stop.
 
I also favor single flute & zero flute countersinks. They work the best for me.

I bought a box of countersinks & centerdrills from a local retired machinist. Most of the CSs are single flute, all US made. In the box were also some multiflute CSs, some with spiral flutes. I mainly use the single flutes on my lathe. The multiflutes also work well but I find I need to feed them much faster/harder than the single flutes to avoid chatter. Like the others I spin all my CSs slow.

In the box were also some of those threaded shank CSs with pilots that screw onto an extended shank. Not sure what they are called but they are used in the aircraft industry. The guy used to work at Lockheed or something like that. They're 2 or 3 flute & also work well but I only have them in smaller sizes. Great for reaching into a hole or a hole that is in a deep area.

On my mill I like using the zero flutes. On my mill, sometimes the single flutes won't countersink concentrically with the hole, they'll sometimes wander. I thought maybe the CS I used was dull or something but it happens randomly. I'm sure it's just my mill's quill. Multiflutes don't wander for me & neither do the zero flutes. Doesn't happen on my lathe though with single flutes and the multiflutes tend to chatter on my lathe.

I got a set of KEO cobalt zero flute CSs brand new in case for dirt cheap, I love them. From the same seller, later I also got a set of KEO 6 flutes. I haven't used them much but they were dirt cheap too so I hopped on the set.


Why is Weldon CS so popular? Is it the range that they can CS? I have not seen another CS brand that has this range.

When I was searching for zero flutes, it seems like the Weldons are most popular even though others make them now. They don't actually have Weldon shanks, it's the brand as you know. Maybe back then they were the first to make them?
 
Will, are you using your CS's on steel or aluminum? Do the zero flutes work well on steel? Have you used them on tool steel?
 
I use my single flutes on alumn, brass, delrin, steel, SS, & titanium gr5 without issues.

My zero flutes I have only used on mild steel & non ferrous so far. I have not tried them on tool steel or Ti.
 
I don't expect a zero flute to hold up well against steel in general. The thin edges just won't hold up.
I'll try my 3 flute HSS countersinks. I also have a new Melin Tin coated, cobalt CS that I'll test against tool steel.
 
Are the zero flute CS's easy to sharpen? How?

Yes, they are easy to sharpen. You just run a grinding stone (Dremel sells these) inside the hole, keeping the stone flat against the inside wall of the hole. The outside shape is untouched; you are bringing the cutting edge to sharpness on the inside or interior edge. I have zero flute countersinks that must be 20 years old and cut like new. I don't sharpen the outer cone; it requires a special grind and I haven't found it necessary to sharpen it this way.

The zero flute countersinks will cut steel, tool steel, stainless, aluminum and brass with no problems. Keep speed down around 100 rpm and feed to produce a continuous chip.

Single flute cutters produce a more precise shape, at least in my opinion. You buy them to suit the angle you need and these also need to be used at low speeds because you only have a single flute cutting. A positive feed and cutting oil produces a continuous chip to give you an accurate taper. Those from MA Ford seem to hold an edge better than others I've tried but they're expensive for what they are.
 
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