Countersink bits, does more flutes mean less chatter?

Sorry to be late in on this, I have 6 flute, 5 flute and Weldon countersinks. I have recently moved to carbide insert chamfering mill cutter for my larger countersinks (1/2" and larger, though it could go smaller). It does a better job than anything elsie I have used. No chatter!!!

When I have smaller holes to countersink, I'll try to report back to this thread.
 
Thank you all for your posts, keep it coming ,
Bob, thanks for the video, it's now clear how it's done.
 
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Hi Guys,

I'll probably get blasted for this, but never sharpen a Weldon countersink with a Dremal ! You cannot get the edge angle correct. Yes as demonstrated it will cut, but it won't cut well.

Use a round stone, by hand, from the inside out towards the cutting edge. Never the other way !
If that edge is damaged you definitely need to use a jig to resurface the outside surface of the cone.

Weldon countersinks are quite easy to make, but you do need to be able to harden the drill rod and you do need a jig to sharpen them properly.
 
Ken, the link in your first post is for an 82 degree countersink. I suggest you purchase a 90 degree one for metric screws instead to ensure full contact with your M8 screw.

Keo, Weldon and MA Ford make some of the finest zero-flute countersinks in the industry. In fact, anything that MA Ford makes is top shelf but you can't go wrong with any of them. I highly recommend staying away from the Asian versions.

I've been using and sharpening these zero flute guys for a very long time. I use a hand drill, not a Dremel, but I use Dremel stones and sharpen from the back side of the hole. Conveniently, the inside of the hole acts as a nice guide to position and maintain the proper angle on the stone and allows you to sharpen the front cutting edge quickly and easily. You just keep the whole length of the stone against the inside of the hole and go around the cutting edges. Takes a few seconds to do and you have a sharp tool. I like the lavender colored Dremel stone, not sure of the grit. I use a hand drill or a Foredom - Dremels go too fast.

Zero flute countersinks actually run well at higher speeds. The small ones can be use at speeds of about half or more of normal drilling speeds. However, they last longer and cut just as well at low speeds, between 100 and 250 rpm.

When the hole is freshly drilled and gnarly in steel, with all sorts of hard stuff sticking up, I use a hand-held zero flute bit in a handle to knock those bits off before using a sharp countersink. Lasts longer that way.

For the single flute bits (I really like single flutes from MA Ford), use them at low speeds and feed hard enough to make sure they cut continuously. When I need a really nice countersink, like one that has to locate a tool, I use a sharp single flute bit from MA Ford. I have never had an MA Ford countersink chatter this way and the finish is excellent.

Multi-flute bits are horrible. I only use them in wood and plastics and only hand held in a handle.
 
Thank you all for helping me with my question , you have also helped me make the right choice even though there were more than one .
I went ahead and ordered the zero flute by KEO. , the price was just right and I thought I couldn't go wrong with that type of countersink bit.
Mikey, thank you for all the info in your post, I did order the 90° since almost all my screws are in metric so that was a very good recommendation.
As far as sharpening of it goes , I'll( very carefully :))follow your suggestion which is almost like the video in Bob's post. but I am now really curious to know the sharpening method BaronJ mentioned . being a lefty, I may find one method easier to follow than the other.

You all have great day now.
 
I have found that an 82* single flute is by far the most useful.
 
I have a single flute counter sink which is my prefered counter sink, I also have a couple of two flute ones that are also very good, I find the 6 flute ones prone to bouncing and not making a nice counter sink.

:)
 
I have found that an 82* single flute is by far the most useful.
I've read that Metric flat head screws have a different angle and the 90° CS bit is often mentioned when using metric . for my hobby use I shouldn't be too fussy .
 
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