Advise on countersinks

[Eric Smith]

When I got started into all this mess  I bought a 1/4 inch titanium Hitachi made counter sink at Lowes ( 95.3% of everythink I own came from either Walmart or Lowes). But it does not seem to cut well in brass. What do you look for in a countersink for our puposed and materials, usually brass or mild steel?

[docone]

I use stone setting burrs. They are high speed steel.
Rub them on beeswax, and make a counter sink.
High speed steel.

[Acer Saccharum]

I like this kind the best. MSC, Enco, or McMaster-Carr. Single lip countersink, 82 degree angle for flat head screws.




For grab-less brass drilling, stone or grind a flat on each leading edge of a drill:

[David Rase]

The hardware store variety countersinks usually have evenly spaced flutes which can cause chatter.  A single flute countersink like Tom posted works well or you can purchase a chatterless one from a machine tool supply house, e.g. MSC, Enco has one of the flutes offset so you can cut a smooth clean countersink.
David

[Acer Saccharum]

Dave Rase, I think the 'chatterless' kind has five flutes.  The common hardware store style has six, which sets up a chattering pattern that is impossible to get rid of.

I use both the five flute kind and the single, and like them both. I am so skilled, I can get the chatterless to chatter, but not often. If I give it enough Jameson's, it will talk your ears off.

I have a slight preference for the single. One size covers a wider range, sharpened to a point, thus does a smaller CSK, and is easily resharpened.

[cmac]

Track of the wolf sells the single fluted ones. I believe in 3 sizes. They require some sharpening off and on but work well

[Don Getz]

While I have never tried this, I heard that if you are getting chatter with a countersink, you should place a sheet of "toilet paper" on the object and it will eliminate the chatter.  Don't want any wise comments about this, it is supposed to work.
Don

[Bob Roller]

 Acer,
That sound like me. I sometimes think I can break an anvil with a rubber hammer.
The uneven number of flutes will do a smooth job and do it even better if they are not evenly spaced.
In 1960 I made a five flute chambering reamer for the 50-110 Winchester cartridge in Bill Large's shop
and Bill told me not to worry about precise indexing and concentrate only on the clearences and primary
cutting edges. It work like a dream and I used it to chamber an 1874 Sharps barrel Bill made for me. I test fired it
and even with no working extractor,when the block was dropped open,a light tap of the butt plate on the ground
caused the fired case to fall out of the chamber.The fired case would also go into the chamber of the M1886
Winchester I had in that caliber as well without resizing.

  Bob Roller

[C Wallingford]

While I have never tried this, I heard that if you are getting chatter with a countersink, you should place a sheet of "toilet paper" on the object and it will eliminate the chatter.  Don't want any wise comments about this, it is supposed to work.
Don

Don--
That works. I use a double thickness of a paper towel , slow speed on the drill and it works.

[bluenoser]

While I have never tried this, I heard that if you are getting chatter with a countersink, you should place a sheet of "toilet paper" on the object and it will eliminate the chatter.  Don't want any wise comments about this, it is supposed to work.
Don

Don--
That works. I use a double thickness of a paper towel , slow speed on the drill and it works.

This is quite interesting.  A little clarification please.  I am having difficulty visualizing it.  Does one place the TP/PT on the work piece and countersink through it or around the piece as a spacer/damper between the piece and the vise or clamp?  I assume you don't just lay the TP/PT across the work piece somewhere.

Laurie

[Acer Saccharum]

Caution: If you leave the TP attached to the roll, you may end up with a big wad of TP spinning around the chuck. Makes it hard to see the workpiece.

[docone]

I have had days like that.
How about using beeswax and light pressure?

[D. Taylor Sapergia]

I just have a set of three flute countersinks, and I use a couple of cleaning patches rather than the After Dinner Roll.  The cloth/paper fills the flutes to a certain degree, and allows only the cutting edge to engage.  I use the slowest speed my drill press will give me.

[davec2]

Don,

I don't use toilet paper (for the very reason Tom points out) but if I experience any chattering, I put a cloth cleaning patch between the countersink and the work piece wetted with cutting fluid.  This will , usually, even clean up a chattered surface.

Over and above that, I use "zero flute" countersinks and have never had a chatter problem with any size in any material.  I threw away all my other countersinks.  I don't think Tom, even with all his talent, could make one of these chatter.

http://www.mcmaster.com/#countersinks/=iylggo      (Click on the "Anti Vibration / Through Hole Countersinks")

or here     http://www.amazon.com/Champion-CSK-SET-5-82-Degree-Countersink-5-Piece/dp/B001TREYFK

[BJH]

This may sound a bit screwy. I dril a small pilot hole in every thing I countersink, like 5/64 dia. Then countersink to about 1/3 finished dia. Double check for positioning errors, fudging is easy at this point. Then finish the countersink to finish dia. The small pilot hole reduces or eliminates chatter. Also if fudging was needed it's easily done with a chisle mark or two on the side you need to walk the countersink to go. Not finish drill to clearence dia. It will follow the funnel of the countersink nicely. This setup works really nicely in the drill press with a center to center jig too.  BJH

[Kelhammer]

I like the single fluted type.  Them are the only kind I own.  As mentioned a slow rpm is required for a nice cut.  By slow I mean under 350 rpm.  My guess is most of the chatter problems will go away by simply slowing down the rpm, no matter the number of flutes. 

[Acer Saccharum]

BJ, you then open up the hole after you've countersunk it?

[Mike Brooks]

I like the chatter.....

[BJH]

Yes Tom, I redrill the hole to the corrrect clearence size. The countersink funnels the drill bit nicely for true position. I allways use this method when drilling and countersinking a tang bolt hole. The small pilot hole and 1/3 dia countersink allows some fudging if I am a hair off center, I use a couple of light chisel cuts to move the countersink in the direction I need. I nick the side that I need the countersink to "walk"to. then go to finish dia and clearence drill the hole. Part of this I learned from my old machine shop theroy book from High School. BJH

P.S. I guess I need to proof read my posts better!

[Meteorman]

I use a couple of light chisel cuts to move the countersink in the direction I need. I nick the side that I need the countersink to "walk"to.

well that's fascinating.
sounds like something that would bail me out time and time again ! 
have any pictures of these chisel nicks ? -  I don't have a feel for what they would look like....
/mike