How should it be done properly?
What size is the hole normally drilled? Does the pin taper? What else is there to know?
Thanks. Sincerely,
-Don
Put your knife on top of the saya, so that the handle is flush against saya side's edge. Mark where you want your pin hole. I typically drill it flush against the heel, but you might want to give yourself a little room for error.
If you make your own sayas, it makes sense to drill a pin hole on the cavity side before gluing, and then transfer it to the other side.
Most Japanese sayas are without distal taper, so you don't need to worry leveling it when drilling a hole.
Holes on Japanese sayas vary, Masamoto can ship with a tiny pin hole, while Nenohi are close to 4.5-5mm.
I find best hole size for me to be about 4mm, not too big and not too small. Bamboo skewers are about 4.5mm, so should you need a source of cheap pins, those could be had in abundance.
I make pins myself, so I normally shape them to fit 4mm hole. I do taper my pins.
M