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View Full Version : countersinks, what say you



loose nut
10-02-2014, 09:33 AM
I need some new, as in not as dull as paper, countersinks and I want to know which type are better. Single flute, multiflute or the funny looking ones with the hole through them at an angle. I haven't had much luck with them in the past, getting a lot of chatter with the multiflute type, so I might change the type I use.

What do you guys use and like.

Stepside
10-02-2014, 10:03 AM
I have found that slowing down the RPM and feeding slow seems to make most types work better. My first choice is one with a pilot matched to the hole, my second choice is the correct size of the ones with the angled hole. A bit of cutting fluid helps a bunch.

Rich Carlstedt
10-02-2014, 10:08 AM
A Ford Style single flute C/S is the best in my opinion.
You cannot over feed it as the ground profile of the cutter controls flute load
and that means smooth C/S's every time

Rich
Edit
Meant to add that using a Ford Style is easy when you do not use a depth stop on the drill press- free hand !
Other cutters usually use a stop because of variable feed rates/pressure

Toolguy
10-02-2014, 10:09 AM
I find the same as Stepside. The ones with a hole are called Zero Flute. With those when you countersink a hole of the screw the c'sink was made for, you go just a little past where it goes vertical and that is the right depth for that screw head. They come in sets, but can be expensive.

MotorradMike
10-02-2014, 10:12 AM
i like the 6 flute carbide ones made by M.A. Ford.
KBC carries them.

_Paul_
10-02-2014, 10:50 AM
Tried quite a few types and always come back to these:

http://festoolownersgroup.com/other-tools-accessories/what-drill-bit-for-countersink-holes-in-new-phenolic-router-plate/?action=dlattach;attach=107891;image;PHPSESSID=a2t c1qgn1k0fal84v5om5vuni0


These give less chatter and a good finish, sharpen with small Dremel drum or round diamond file.

Paul

Paul Alciatore
10-02-2014, 11:47 AM
Ditto! These have the least chatter. But be sure that you get a good brand. Some of the inexpensive ones are not properly relieved and they don't cut well. The good ones cut great.




Tried quite a few types and always come back to these:

http://festoolownersgroup.com/other-tools-accessories/what-drill-bit-for-countersink-holes-in-new-phenolic-router-plate/?action=dlattach;attach=107891;image;PHPSESSID=a2t c1qgn1k0fal84v5om5vuni0


These give less chatter and a good finish, sharpen with small Dremel drum or round diamond file.

Paul

Mike Folks
10-02-2014, 12:13 PM
The above type in 100 degree, is used for de-burring drilled holes in Aluminum in Aerospace parts, usually free hand, with a Pneumatic drill. "Weldon" is the popular brand seen at most Aerospace companies.

http://drillsandcutters.com/countersinks/?utm_source=bing&utm_medium=cpc&utm_term=weldon%20countersinks&utm_content=6752681253&utm_campaign=countersinks

projectnut
10-02-2014, 01:05 PM
I purchased a set of Ford uniflute 82* countersinks over 30 years ago and still have them today. They were resharpened once in the 20 years I worked in a machine shop. Over the years I've found this style much better for hand deburring than any other style. I think I've used every style on the market in both carbide and HSS and the uniflutes seem the most durable. The multi flute styles work well in a mill or drill press, but not as well when used in a hand drill. They're more likely to chatter, and eventually chip a cutting edge.

I probably have 100 different countersinks in different angles, flute style, and material. The Ford uniflutes are by far my favorite.

Bob Fisher
10-02-2014, 01:06 PM
I'm partial to the single flute styles, again, buy good quality! McMaster Carr carries some good ones . Been using a set of five for about three years in our shop and have not needed to replace even one. Bob.

DR
10-02-2014, 02:05 PM
Tried quite a few types and always come back to these:

http://festoolownersgroup.com/other-tools-accessories/what-drill-bit-for-countersink-holes-in-new-phenolic-router-plate/?action=dlattach;attach=107891;image;PHPSESSID=a2t c1qgn1k0fal84v5om5vuni0


These give less chatter and a good finish, sharpen with small Dremel drum or round diamond file.

Paul

Those are commonly known as "fish eye" type. They're best for light deburring. Weldon (I believe) was the inventor and they used to say only for non-ferrous de-burring.

They are not designed to be sharpened by grinding the hole (the more you grind the more fragile the cutting edge becomes). Weldon and MA Ford both make grinding fixtures to do the OD.


For the ultimate in heavy duty countersinking the Severance multi-flute type are the best. They have an unusual grind that prevents chatter (that grind also realistically prevents home re-sharpening).


On edit: I noticed Weldon calls the fish eye style de-burring tools, not countersinks.

Frank Ford
10-02-2014, 02:49 PM
. . .The Ford uniflutes are by far my favorite.

Same here. I ended up with a full range of those things, and I'm surprised at how often I use the 60 and 100 degree ones for "cosmetic" chamfering of holes.

aboard_epsilon
10-02-2014, 03:07 PM
all I can tell you is make sure they have hex shanks on them or the torque will cause them to spin in the chuck, because of the small shank diameter verses the large head ratio.

all the best.markj

Paul Alciatore
10-02-2014, 09:57 PM
I have always heard them called O flute countersinks. I use them for both countersinking and de-burring. They can de-burr both holes and external edges. Very useful.

Weldon may call them de-burring tools, but other manufacturers DO call them countersinks. And the fact that they are sold in all the common countersink angles reinforces their suitability for that use.

As for sharpening, I have been told both ways, inside the hole and on the external "cone" (which isn't a cone at all). Both ways have advantages and disadvantages. In the hole, you widen the hole, but you can get several sharpenings that way before it becomes objectionable. I have rolled up some crocus cloth and used an in and out motion in the hole. On the external cone-like surface you have to be careful to preserve the proper relief angle on the half of the hole that does the cutting. This is what is wrong with cheap ones that are improperly sharpened and is the reason they cut poorly. This relief angle is very shallow and continues all the way around the cone until it reaches the other side of the hole. So half of the hole's edge is raised and the other half is depressed and there is a small zone between them where it slopes from one to the other. This geometry is hard to do at home but, with care, you can HAND stone them all the way around, rotating the countersink as you stroke it on the stone. This is good for a touch-up sharpening, but would take forever to actually form the edge that way. And again, it is only good for a limited number of sharpenings. Both of these sharpening methods will cause the cutting edge to become smaller.

Oh, and they do produce less chatter than the single flute countersinks. Don't ask my why, they just do. Probably has something to do with cutting along an arc instead of a straight line.



Those are commonly known as "fish eye" type. They're best for light deburring. Weldon (I believe) was the inventor and they used to say only for non-ferrous de-burring.

They are not designed to be sharpened by grinding the hole (the more you grind the more fragile the cutting edge becomes). Weldon and MA Ford both make grinding fixtures to do the OD.


For the ultimate in heavy duty countersinking the Severance multi-flute type are the best. They have an unusual grind that prevents chatter (that grind also realistically prevents home re-sharpening).


On edit: I noticed Weldon calls the fish eye style de-burring tools, not countersinks.

KiddZimaHater
10-02-2014, 10:28 PM
In my personal experience, I like single-Flute countersinks.
They seem to 'bite' better, with less chatter.
When the 4 or 6 flute countersinks start to get dull, they chatter like crazy.
Single flutes are easy to sharpen too.

J Tiers
10-03-2014, 12:11 AM
Multi-flute seem to ALWAYS chatter, mostly because of their design. If made like the others mentioned by one poster above, they probably have stagger-spaced flutes, and chatter less. The single hole types don't chatter at all.

Lew Hartswick
10-03-2014, 10:03 AM
If you have chatter with multi flute ones youre turning the thing too fast OR not enough feed OR BOTH!
...lew..

Sun God
10-03-2014, 01:01 PM
Yes the multiflute countersinks are a bit of an oddity, in that they need to be fed slower and harder than one would think, and as a consequence either cut too deep too fast, or chatter like crazy. If used properly they need a bucketload of low end torque.

J Tiers
10-03-2014, 10:15 PM
If you have chatter with multi flute ones youre turning the thing too fast OR not enough feed OR BOTH!
...lew..

With some, no sensible drill press likely to be in a home shop CAN feed that hard..... Better to just use a different C-sink.

DR
10-03-2014, 11:05 PM
With some, no sensible drill press likely to be in a home shop CAN feed that hard..... Better to just use a different C-sink.

We use the Severance countersinks in my old 1950-ish Atlas/Craftsman dp's all the time (love those Atlas machines, smoothest running dp's I've found). No problem at all and they don't chatter, either fast or slow rpm.

Your typical multi-flute countersink is a cheapo like General or some other secondary manufacturer. They have a neutral rake on the cutting edges. As with most things machining-wise you get what you pay for. If you're big into countersinking spend the money.

It's no surprise a multi-flute will need more feed, after all you are trying to cut with 3 or more flutes.

J Tiers
10-04-2014, 09:43 AM
Your typical multi-flute countersink is a cheapo like General or some other secondary manufacturer. They have a neutral rake on the cutting edges. As with most things machining-wise you get what you pay for. If you're big into countersinking spend the money.



Eh? "General"? who's that?

Looked at mine... Grobet, Schrillo, Weldon. Those are the names I read. Others had logos I didn't immediately associate with a name..

RogerP
10-04-2014, 10:08 AM
I have a Ryobi EDP5530 pillar drill with mechanically variable speeds between 500-2400rpm. Not exactly a top of the market machine I know but I got it on a close-out sale very cheaply and it does the job.

The point is that with its infinitely variable speeds I've discovered there is always one point where any countersink will give of its best and usually this is over a very narrow speed range.

Previously bits cast aside as junk can actually work well when used at precisely the right speed for the material being machined. Usually the best speed is much slower than I'd have thought to try without this easy means of experimentation.

Roger