Countersink choices

[Peter CaswellParticipant @petercaswell93233]

Hello members of MEW Forum, this is my first post so please forgive me for any errors in protocol.

Could I please request the members to share their experiences and views of countersink bits.

I wish to replace my old HSS multi flute ones which I have never been entirely happy with regards to the concentricity of the countersinks they form and slow cutting (probably because of dull cutting edges), also the difficulty of re-sharpening, which I have neither the experience or equipment to do so. The types of countersink are many and of course manufactures and sellers favour the ones they make/sell. Also the cost varies widely from a few pounds for a set from the far east to upwards of £70 for one cutter from well known brands and a whole host in between. In advance of advice, for ease of resharpening maybe I favour single flute cutters. I would particularly welcome any experience of far east ones as I have had reasonable experiences of end mills from there, which are cheap enough to throw away (after use I mean!).

Thank you.

[Peter CaswellParticipant @petercaswell93233]

[David George 1Participant @davidgeorge1]

Hi Peter first welcome to the forum. I have many countersinks mostly made by myself but the best set are ones from Dormer they came in a set and have lasted at least 15 years withoug re-sharpening. It depends what you are countersinking and how deep your pockets are to what you buy I think that you could buy a few sets for the price of mine. Here are a picture of a few of mine some made from old drills etc.

David

[Speedy Builder5Participant @speedybuilder5]

If you want precision countersinking ;-
**LINK**

The holder gives the adjustable depth for the rivet head, the various cutters have different pilot diameters. But I doubt you wanted something this expensive / accuracy. I find the 'snail' type give good service.
BobH

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Speedy Builder5 on 30/01/2019 08:23:50:

If you want precision countersinking ;-
**LINK**

Thanks for that link, Bob

100° countersink angle noted

… It looks good value [do you have one?]

MichaelG.

[JasonBModerator @jasonb]

I tend to use the Ruko 3-flute ones and have not found the need to sharpen them. That really depends on what you are using them for, a lot of large CSK holes in black bar will wear them faster than small CSK holes in brass and ali

[Roderick JenkinsParticipant @roderickjenkins93242]

I've been very happy with these single flute countersinks **LINK**

Rod

[Douglas JohnstonParticipant @douglasjohnston98463]

I find the Weldon style zero flute type tend to be more forgiving than other types and cut very cleanly when sharp. Not so easy to sharpen though where the cutting face is formed by an angled hole through the cone shape.

Doug

[pgk pgkParticipant @pgkpgk17461]

Posted by Douglas Johnston on 30/01/2019 09:53:02:

I find the Weldon style zero flute type tend to be more forgiving than other types and cut very cleanly when sharp. Not so easy to sharpen though where the cutting face is formed by an angled hole through the cone shape.

Doug

I've not had need to sharpen mine yet but always planned to spin it up in a cordless drill and offer it up against the belt sander?
What I like about them is one can debur a hole quickly in a hand chuck.

pgk

[John BaronParticipant @johnbaron31275]

Posted by pgk pgk on 30/01/2019 10:39:22:

Posted by Douglas Johnston on 30/01/2019 09:53:02:

I find the Weldon style zero flute type tend to be more forgiving than other types and cut very cleanly when sharp. Not so easy to sharpen though where the cutting face is formed by an angled hole through the cone shape.

Doug

I've not had need to sharpen mine yet but always planned to spin it up in a cordless drill and offer it up against the belt sander?
 

 

pgk

Don't do that, you will quickly ruin it !

Weldon single hole countersinks have a tapered cone ! You can see it if you use a pointer aligned with the edge of the cone and rotate the countersink. There is about 20 thou of taper on them.

 

 

Edited By John Baron on 30/01/2019 11:18:07

[Peter SansomParticipant @petersansom44767]

Single flute can be used in a hand drill.

Cross hole good for deburring and counting sinking, limited hole size per countersink. Problem sharpening if necessary. Can use in hand drill.

3 Flute, needs to be using in a lathe, mill or drill press to produce a good countersink.

[Peter CaswellParticipant @petercaswell93233]

Posted by pgk pgk on 30/01/2019 10:39:22:

Posted by Douglas Johnston on 30/01/2019 09:53:02:

I find the Weldon style zero flute type tend to be more forgiving than other types and cut very cleanly when sharp. Not so easy to sharpen though where the cutting face is formed by an angled hole through the cone shape.

Doug

I've not had need to sharpen mine yet but always planned to spin it up in a cordless drill and offer it up against the belt sander?
What I like about them is one can debur a hole quickly in a hand chuck.

pgk

Thanks Doug and pgk (learning may around on this forum, is this the right way to thank replies to a post I made?)

[Peter CaswellParticipant @petercaswell93233]

Posted by JasonB on 30/01/2019 09:01:22:

I tend to use the Ruko 3-flute ones and have not found the need to sharpen them. That really depends on what you are using them for, a lot of large CSK holes in black bar will wear them faster than small CSK holes in brass and ali

Thanks Jason, found a 12.4mm Ruko 3 flute at a reduced price at £7.30 (ex VAT) instead of £12.17 (ex VAT) but don't know if that is a good price?

Note your comment about black bar not something I have not used much of to date.

[Peter CaswellParticipant @petercaswell93233]

Posted by Speedy Builder5 on 30/01/2019 08:23:50:

If you want precision countersinking ;-
**LINK**

The holder gives the adjustable depth for the rivet head, the various cutters have different pilot diameters. But I doubt you wanted something this expensive / accuracy. I find the 'snail' type give good service.
BobH

Speedy Builder5 not what I am really looking for but it is interesting bit of kit and thanks, Haven't looked to see if these available in the UK but will do so out of interest.

[SamsarandaParticipant @samsaranda]

The aircraft type, referred to in the link above by Speedy Builder5, are the best that I have used, we used them when carrying out repairs and modifications to aircraft fuselage structures. Their main advantage is they are held square to the work by the outer barrel and their depth of cut is regulated by very fine adjustment which ensures that when countersinking for rivet heads you can get the depth of countersink spot on. It all depends what you are countersinking whether it is worth the expenditure.

Dave W

[John ReeseParticipant @johnreese12848]

For single flute countersinks I sharpen by grinding the inside of the cutting flute so I do not disturb the clearance on the outside. On zero flute countersinks I grind the inside of the hole until the wear land disappears.

[Neil WyattModerator @neilwyatt]

I tend to prefer single-fute ones, both bought and shop-made.

Three flute HSS ones work well, but more flutes than that and they chatter badly (I think multi-flute ones are meant for wood).

Neil

[Peter CaswellParticipant @petercaswell93233]

Posted by Neil Wyatt on 31/01/2019 12:34:34:

I tend to prefer single-fute ones, both bought and shop-made.

Three flute HSS ones work well, but more flutes than that and they chatter badly (I think multi-flute ones are meant for wood).

Neil

That what I have found Neil, the HSS multi flutes just don't seem to cut steel, of course it could be me, I must confess to date I have used same ones in both hand tools and machine tools, my new ones will be dedicated to machine tools. I have ordered a set of single flutes following the link that Roderick Jenkins kindly posted.

[JasonBModerator @jasonb]

2 flute TCT ones are what I tend to use for wood, they last a lot better in man made and coated boards.

I've used the ARC ones for my milling articles and they seem OK

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