Counter Sinking Tang Bolt

[Nhgrants]

I have the tang bolt drill thru the tang and threaded into the trigger plate.
What is a good way to counter sink the head of the bolt into the tang?
Thanks

[Ed Wenger]

I have good results using a centering drill, believe a #5. 


           Ed

[okieboy]

 One can use a center drill, but remember flathead imperial (inch system) screws are 82 degree, most center drills are 60 degree. But you can purchase 82 degree center drills from an industrial supply house. And to make complete, metric flathead screws are 90 degree. 

[Lzymtlsmth]

Counter sinks available too with correct angle.

[Sidelock]

I really like the chatterless counter sinks by M.A. Ford - they cut soft steel like butter and leave almost a mirror finish in the counter sink.

[RJD-VT]

I agree with Sidelock. I retired as a quality manager in a small machine shop. I only ordered Ford counter sinks for the whole shop. No chatter and happy customers  I think we got them from MSC.

[Flint62Smoothie]

I only ordered Ford counter sinks for the whole shop. No chatter and happy customers  I think we got them from MSC.

Here you go, 1/4” shank, 1/2” diameter Ford counter sink from MSC Fasteners, only $18.30 each.

https://www.mscdirect.com/product/details/01051325

Picture of 3/4” one shown.

[Dennis Glazener]

I use these: https://www.mscdirect.com/product/details/01036045
Available in several sizes just be sure the tip is right side for the shank of your screws
Dennis

[Metalshaper]

remember to put a heavy piece of card stock between the part and the  countersink.  that way as you start, the 'sink' cuts through the card stock and eases its way into the metal.
Help to stop the chatter you can sometimes get from straight on countersinking..  done right it can even take out chatter from a previous attempt.. I have also used a denim square
from the rag bin.

Works for me!

Respect Always
Metalshaper/Jonathan

[Flint62Smoothie]

I use these: https://www.mscdirect.com/product/details/01036045
Available in several sizes just be sure the tip is right side for the shank of your screws.

Only $6 each ... good find Dennis!

[Mauser06]

I will show my ignorance....


How do you know what size countersink you need???  Or will the same one work as long as the cutter is within the size range you need? 


I haven't had an "issue" but something so "simple" takes a little trial and error to get right. 

[Lzymtlsmth]

Same cutting angle, larger ones the bevel diameter larger.

[flehto]

The stock/bbl ass'y is clamped in a vise atop my drill press 3'X5' 3/4" plywood  table top and the tang bolt clearance  hole is  drilled but only slightly   "dimples" the trigger plate . The tap drill for the trigger plate is drilled through and the hole is tapped using the clearance hole as a guide. Mike the dia of the tap body  to determine the clearance drill dia.

The ctsk used is a standard angle , single lip and smoothly cuts the ctsk. While ctsking, the tang screw head is used to gage the ctsk dia. The ctsk dia is less than the screw head dia and the screw head  dia is filed down by chucking in a drill press  The hole and ctsk are cleared of chips and the tang bolt is screwed in. Some  of the above  description is basic stuff, but perhaps will be informative to some.

This is all done w/ the bbl/stock ass'y clamped in the vise atop the "table".......Fred

[P.W.Berkuta]

I have the tang bolt drill thru the tang and threaded into the trigger plate.
What is a good way to counter sink the head of the bolt into the tang?
Thanks

Counter sinks are run at a SLOW speed if run at a fast speed they chatter also using a piece of cardstock or paper will help eliminate chatter.

[Craig Wilcox]

I have and use ONE countersink, 1/4" shaft, head is 3/8".  Single cut, works great for everything from #4 to #12 FH screws.

[Dennis Glazener]

I have tried that card stock trick and it did not work for me, chatter marks that I could never get out. I do not have that problem with the center drill. Also tried grinding on of the flutes off and that did a little better but not 100%
Dennis

remember to put a heavy piece of card stock between the part and the  countersink.  that way as you start, the 'sink' cuts through the card stock and eases its way into the metal.
Help to stop the chatter you can sometimes get from straight on countersinking..  done right it can even take out chatter from a previous attempt.. I have also used a denim square
from the rag bin.

Works for me!

Respect Always
Metalshaper/Jonathan

[Stophel]

Yeah, the card/paper/tissue trick definitely does not work for me either.  I can't imagine how it works for anyone, actually.   

I use plain, ordinary store-bought countersinks.  I can file the screw heads to match the bevel angle easily enough.  I turn them by hand in a brace, and I use two different ones.  A three flute, and a five flute, changing them up every few turns, so they each cancel each other out, and I don't get a chatter started.

Old countersinks, I am told, were cut by hand and had unevenly spaced flutes, so chattering was not a problem.

[Metalshaper]

Like I said , works  for me!

Respect  Always 
Metalshaper  /  Jonathan 

[Clark Badgett]

I countersink holes daily and have never had much problem with chatter. By hand drill, mill, drill press, just keep the speed under 90 rpm.

[Turtle]

 I use a countersink that has a lot of flutes and it doesn't chatter. I chuck the tang bolds in a drill press and file the bevel angle to be less than the countersink so the outside or the screwhead bottoms first. This helps eliminate any possible gap showing.

[Ray Barbarow]

My preference is to use denim with a good quality cutting oil. I use an old hand brace which will require fairly heavy hand pressure and this also assures that the RPM is slow. This will remove chatter if you use a lighter pressure on the brace.   

[tiswell]

If the cardstock trick does not work try a thin piece of leather. If still no good try a thicker piece. Once chatter starts in a particular piece it is harder to get rid of it.  Generally the more rigid your set up is the less chance that it will occur, but you can get good results with a pistol drill if you play around with it.

[rick/pa]

I used to get countersinks that looked like a triangle.  Now I use a piece of oiled flannel between the countersink and the part.

[Hungry Horse]

You guys do realize a nineteenth century gunsmith would likely laugh himself to death over you guys worrying about bolt head angles, and chatter marks, and heaven knows what else. It seems to me this has gotten to be  more about tool collecting, than replicating early American gunsmiths work.

  Hungry Horse

[P.W.Berkuta]

The old time gunsmiths did not get chatter because they used a bit & brace and cranked it SLOWLY slowly is the key to success . Most people that have difficulty with countersinking also have problems with drilling a simple hole .