Neither drill nor ream to countersink for the hinge pin.
Instead, use a bur that "flares" the inside opening at an angle
of about 45 degrees.
Alan, Could you be more specific regarding the type of bur
you use to flare the inside opening. Thanks.
I have used a variety of burs, because many different styles
have a tapered end. Any setting bur, hart bur, bud, or flame bur
will work, so long as it is large enough not to slip inside the
tubing. Therefore, when inserted, it removes the squared off
inner corner and cuts a small angled rim which provides a
"shelf" for the flared pin to grab onto. Hope this is clear, but
if not, perhaps Peter, Charles or others can be more articulate
this early in the day.