T47 is a bottom bracket standard that White Industries helped develop in 2016. The “T” stands for “threaded” and the “47” is the approximate outside thread diameter of the cup, in millimeters. T47 bottom bracket cups are not compatible with the much smaller BSA threaded BB shells.  The “external” designation on this bottom bracket refers to the fact that the bearings sit “outboard” of 68mm and 73mm wide bottom bracket shells, as opposed to our “internal” T47 bottom brackets where the bearings sit “inboard” of 86mm and 92mm wide bottom bracket shells.  If you have an 86mm or 92mm wide T47 bottom bracket shell on your frame, you will need one of our “internal” T47 bottom brackets to work with our 30mm M/A/R/G cranks.
 
White Industries external T47 style bottom brackets are made here in our shop with U.S. sourced 6061-T6 aluminum and feature Enduro stainless steel anglular contact bearings or Enduro XD-15 ceramic radial bearings where available.  We offer them with four different bearing sizes to help you fit your favorite crank to your favorite bike.
 
NOTE: Rolling production schedules and international shipping mean turnaround on White Industries products can take up to 6 weeks