TromboneChat

Hello,

Some manufacturers call their throat sizes in letters.
How is the diameter of an A, B, C, D, E, F, throat?

Many times these are the drill sizes used to make the throat.  An E drill is 0.250" (you can convert to metric yourself).

There are drill size charts for letter drills on line with metric equivalents.

Here is an example: http://www.csgnetwork.com/drillsizeconvert.html

thanks Bruce

thanks Bruce