Transfer punches have a tip shaped like you describe.
--- In Homebrew_PCBs@yahoogroups.com, James <bitsyboffin@...> wrote:
>
> On 09/04/13 13:32, David Halbakken wrote:
> >
> > James, what tool are you using to peen the rivets? I did not notice
> > any tools specifically for that purpose on the taobao site.
> >
>
> I did some testing with "peening" the rivets tonight, I got the best
> results by inserting from the "presentation" side, then using a very
> sharp fine point (I ground a point on a 1mm or so rod, but just a
> drawing pin would work) on the bottom of the rivet to enlarge the hole
> slightly (insert point and a couple of light taps, or just work in a
> circular motion by hand), then pressing it using a 10mm flat ended rod
> chucked in my drill press.
>
> Enlarging the hole on the bottom side makes them press more evenly,
> otherwise they tend to collapse to one side or split to both sides
> causing the bottom to press out quite far in at least one direction.
>
> I tried making a spike-and-press tool in one (a very fine and short
> point in the center of the end of 10mm rod diameter something like
> http://www.flickr.com/photos/93638530@N08/8643991549/in/photostream )
> but I was unsuccessful in constructing it with my grinder, if I could
> construct it, I think that would work well in a drill press. I've
> thought that maybe there is some other way to make it. Grind a point on
> the end of an old 0.8mm drill shaft, drill a 0.8mm hole in the end of
> the 10mm rod, insert the pointed shaft with some epoxy to the right
> depth. Still much easier said than done drilling 0.8mm hole into a
> steel rod. Might work though...
>
> Anyway, I'm thinking to tin the via pads, put some flux on the rivet,
> insert and peen rivet, then apply the iron to heat the rivet and the
> solder under it to ensure a long lasting connection.
>
>
> [Non-text portions of this message have been removed]
>