View Full Version : What type of countersink to buy

10-12-2005, 12:07 PM
I'm looking to buy a "good" set of countersinks such as Weldon, M. A. Ford, or KEO. I understand that I should get an 82 deg. set for machine screws.

However I'm not sure whether I should get the uniflute (single flute) type or the zero flute (hole type). I definitely want something chatterless for metal work. KBC has KEO zero flute countersinks on sale. I read in this board's archives that zero flute sinks should only be used on soft materials, but I can't find any mention of this anywhere in the information that I have at hand. Is this correct or am I in error?

Any comments on which type of countersink set I should get? I'm working mainly with steel, aluminum and brass, with some plastics now and then. If the zero flute sinks are OK for these materials (i.e. general purpose) then I'd like to take advantage of the KEO sale.

Thanks in advance.

10-12-2005, 12:21 PM
Well, I have a KEO single flute 3/4" 82* countersink that I have been using for about ten years now for countersinking and chamfering steel, brass & aluminum. It is the only one I use, and is usually chucked in the DP.

I chamfer all holes to debur and for appearance, so it has seen alot of use. I also use it for most countersinking I am doing, and on occasion have mis-used it to open up a hole to 3/4" in thin material.

I would avoid the single hole C/s's, they are fragile and difficult to resharpen.

BTW, I have not had to resharpen the KEO. YMMV, but you will never get this performance out of import tools.

Herm Williams
10-12-2005, 12:23 PM
I have one flute, three flute, multi flute, and if the material to be cc can be cut with the zero (hole type) I use them. Some material has to be cut with carbide or diamond,if I could find hole type in carbide I would try to get some. What I'm trying to say is that if you start using the hole type IMHO you won't use any other.

10-12-2005, 01:23 PM
I've always used the Weldon hole-type countersinks. They work, but I've never found them particularly spectacular. Next time I buy a countersink I think I'll try something else.

As always with this stuff, your mileage may vary. I would recommend GOOD ones though, whatever you get (which you plan to do, anyway....)

Get a few of each! http://bbs.homeshopmachinist.net//biggrin.gif

Paul Alciatore
10-12-2005, 02:17 PM
I have used several types, including the O and uni flute ones. When I tried the O flute type I stopped experimenting. I find that they work very well. No chatter and they seen to work on everything I try them on. Good for countersinking and deburring.

I even find them easier to sharpen. A small cylinderical or conical stone in the Dremel inside the hole will sharpen them very easily. You can usually resharpen them several times before the hole is too big.

Paul A.

10-12-2005, 10:07 PM
I've been disappointed by Keo twice. A recently purchased 60 degree, 1" single flute countersink had some surface rust out of the package. Not a big deal but it also did not center very well when used without clamping down parts on a drill press.

I have some Cleveland countersinks (single flute) purchased a long time ago which center very nicely under the same circumstances. The finish is also better.

Another KEO purchase was a set of 5 center drills purchased from MSC. They came tossed into a plastic bag and stapled shut. Several had discoloration from the grinding process and NONE had any markings on them !

Next time on countersinks, I'd give MA Ford a try and probably the 0 flutes that Paul mentioned. Den

[This message has been edited by nheng (edited 10-12-2005).]

10-12-2005, 11:31 PM
It's correct that the single flute, Weldon "fish eye" and Ford Uniflute are meant ONLY for soft materials. Catalogs may not list them with that precaution, but the their respective factory literature does. Yes, we occasionally use them for other materials including tough SS. They don't last long in some of the more difficult materials though.

An all around countersink that works in soft and tough materials is the Severance type. They're multi-flute chatterless. Pricewise they may be more than the single flute style, but worth the money. Severance differs from the rest of the industry in their specs, for an 82 degree tool they list it as a 41 degree, likewise 90 is listed as 45.

BTW, Weldon "fish eyes" can be sharpened by grinding inside the circular flute, not a great idea though. It further weakens the cutting edge. Both Weldon and Ford should be sharpened on the OD using the correct relieving fixtures for best cutter life.

10-13-2005, 02:24 AM
Ive countersunk so many holes and i have in my collection aproximately (no ****) around 50 or so) I always use a five piece three flute set i bought a few years ago. They are in a red case and i use them daily in the tool and die shop on d2 a2 4340 4140 01 and all other stuff. They are good and havent chipped or even gotten dull yet. I think theyre import units. $110 for the set. In red plastic box hope this might help good luck.

bernie l
10-13-2005, 08:14 AM
FWIW, if you're buying countersinks for general deburring then 82 degree or 90 degree either will work fine. However if you're purchasing countersinks for flat head screws make sure you get the angle that corresponds to the screws, 82 degree for standard, (or imperial) size fasteners, 90 degree for metric. I found a metric FHCS doesn't tighten down very well in an 82 degree counter sink.

take care