Tang bolt counter sink

[Bonnie54]

Good morning folks. What would be the correct countersink degree for a tang bolt. Also any recommendations on a good chatterless countersink. Your help would be greatly appreciated and enjoy your Sunday.

[tlallijr]

82 degree

[smylee grouch]

Sometimes a solid work piece and tghe use of cutting oil can help

[DGB]

Sir,
In over 40 years of tool and die work, Severence brand chatterless C'sinks are about the best I have used for small holes such as those we have on ML's. The six flutes seem to work the best.
Also, I have found that all of the tang bolt angles are not always as they should be.
Best to always test your drilling and countersinking in a piece of scrap before going to the real job at hand.
Regards,
DGB

[Mike Brooks]

I use a V shaped thingy. Been using the same one for 41 years.

[Bonnie54]

I think I'll try the severance brand 82 degree v shaped thingy using oil on a solid work bench. Thanks gents. Mike, your hilarious

[JBJ]

My preference for countersinks remains the Weldon fluteless countersinks. They are available in 82 degrees, without a pilot, and are sized according to screw sizes. DO NOT buy the imports as I have found the the cutting end not to be concentric with the shank.
J.B.

[Randall Steffy]

Weldon fluteless countersinks everytime.

[smart dog]

Hi Bonnie54,
Counter sinking the hole is fine but counter boring it is better.  I counter bore by drilling into the hole with a 5/16" drill so there is a short vertical wall to the hole.  Then I insert a 5/16" counter sink to shape the bottom of the hole.  Then I turn my tang bolt so it has short vertical sides to the head and to fit the hole exactly.  The value of counter boring is you can then shape the top of the bolt in any fashion you need to be flush with the tang.  This is really important if the bolt goes in at an angle to the tang.  The photos below show a counter bored hole and fitted bolt.

dave

[J. Talbert]

M A Ford brand is the first one I found that truly doesn't chatter.  Been using it ever since.
I've got a drawer full of cheaper ones that all chatter at one time or another.

Jeff

[Scotty]

I like the counterbore idea from smartdog and will be trying it next.

[Mike Brooks]

If you get chatter while you're using your V thingy, put a cleaning patch under it. No more chatter.

[J. Talbert]

If you get chatter while you're using your V thingy, put a cleaning patch under it. No more chatter.

Mike I’ve used that trick with some success, but so far I’ve got two different sizes of the M A Ford countersinks and they just don’t chatter.

Jeff

[Clark Badgett]

I’m with Mr. Talbert. Got the full 82* and 90* sets at work. They don’t chatter.

[Scota4570]

I do what Daves does but different.  I make piloted counter bore reamers that fit the screw.  I use half reamer countersinks that recess the exterior edge of the screws on patchboxes too.  I do not like using a countersink that is larger than the screw.  The oversized countersink hole around the screw head look bad to my eye.  Old allen wrenches are a good source of material to make these reamers.

[P.W.Berkuta]

Countersinks are to be turned at a slow RPM to reduce/prevent chatter. I like using an "eggbeater" style hand crank drill for countersinking screws up to 3/8" in mild steel and brass and a variable speed hand electric drill for anything over 3/8" - SLOW is the key to success. P.S. counterbore is Ok if you are perpendicular to the surface and in line with the through hole this also is true for a countersink. I have use both methods with success - take your time with this operation and make sure your hole is on center of the part or it will look very bad 

[T*O*F]

I do as Dave and Scota, but much easier requiring only 1 step and no machining.  These will counterbore and countersink in one operation.  Then chuck your screw in the drill press and use a file to reduce the head size to the counterbore size, which leaves a flat on the screw head.  They come in 82 degrees for American screws and 60 degrees for English screws.

[Bob Roller]

Day before yesterday I installed a trigger guard on and long bar Hawken trigger and drilled a hole just big enough for an 8x32 screw to pass thru and then a partial bore with a 1/4" drill bit and finished a flat bottom hole with a 1/4" 3 fluted end mill.
Also I went to 5 and 7 flute solid carbide end mills for my trigger making operations with fine results.I do NOT like big gaps between the trigger bars and these mills make it much better and easier to do.They do cost a bit more but who cares if they are right for the job?
Bob Roller

PS:The reason I withdrew these triggers from the For Sale section was that I found a blemish or so I thought inside the bow of the trigger guard and NOT because I didn't get a quick response on a fairly costly item.Here is how I polish the inside of a trigger guard when possible.I bought a low end bench grinder from Harbor Freight that has what passes for a 1/2x13 right hand thread on the right side. and made an adapter with this internal thread to replace the nut that had a 3/8x24 thread shank pointing to the right and then installed a surplus Jacobs chuck on it and using small diameter expanding rubber wheel with an abrasive drum installed the interior of the guard is taken care of with much less effort and a better job as well.
BR

[D. Taylor Sapergia]

When drilling a countersink, take your drill press down to its slowest speed.  Place a cotton cleaning patch over the pre-drilled hole (screw shank diameter), and cut the countersink.  the patch will fill the flutes enough that only the cutting edge meets the subject metal, and the countsink will be clean and chatterless.

[Bonnie54]

Thank you Gentlemen for your advice. Cheers. Taylor I was just reading your wire inletting tutorial. Very well done. Im currently starting a Rupp.

[D. Taylor Sapergia]

Thank you.  I hope id gives you some encouragement.  Good luck with your Rupp build.

[Eric Kettenburg]

The counter bore method that Dave describes above is almost overwhelmingly used on European work, at least I should say pretty much everything I've taken apart.  Barrel tangs and often sideplates and buttplates too.  I've seen it on quite a few American pieces although here it seems more of a mix between the counterbore and the V shape countersink.  Anyway carry on.

[Dan Fruth]

Most folks probably drill and countersink with a hand drill, so countersinking is always difficult. Run the speed slow so you can eliminate chatter. Consistent pressure and  slow speed will always produce a clean c-bore. Good luck

[Bonnie54]

The Welton #6,8,10 countersinks came yesterday. They work magnificently . Thank you folks for the assist!

[Nhgrants]

Quite a while back i think i made a die from 1/2 plate. Drill into it with the counter sink and then a thru
 Hole for the bolt, then heated the bolt head to yellow and pounded the head into the die. Then reshaped the top ofthe head and recut the slot.

Used the same drill and counter sink in the tang,

It took a few tries to get it to work.  Some where just rod and upset one end for a head while others started
Off as machine screws.  May have upset the screw heads to have more metal to work with.
 Basically forged the heads to fit the counter dink.