Are all bridge pins the same size? At least those on guitars made in the last few years?
Yamaha FG730S
No, they are not all the same size. Here is a little guide.

Edit: But there certainly is a little bit of a fudge factor because holes can wear down. Many companies sell "standard" size pins that will probably get the job done pretty well.
Last edited by GC Shred Off at Oct 23, 2009,
Wow! more involved than I thought.

I'd like to upgrade the bridge pins on my FG to horn (horn is black and so are the originals).

I have upgraded the bridge to bone and am having the nut upgraded this week to bone and thought I'd complete the upgrade with better bridge pins.
Yamaha FG730S
No there are several varieties. Martins I believe use a 3 degree taper and some others use a 5 degree taper. Take one out and take it too your guitar store and have them match it. Get bone pins and you will notice a distinct increase in tone and if you change the bridge to bone too you will notice a dramatic increase in tone.

Check out e-bay for bone bridge pins. You can get a set for $10
Thanks for the suggeation. Yamaha support says that they used a 4.5 degree taper and have no clue what top and bottom diameter is.

The bridge pins are the last piece of the puzzle. I've upgrades the bridge and nut to bone already.
Yamaha FG730S
I would probably go ahead and use the 5 degree taper. You sometimes have to sand them anyway to get a good fit. The last ones I got were actually slightly loose and they worked fine.