411 REFERENCE · Wikibooks
Bicycles/Maintenance and Repair/Tools and Supplies/Bottom Bracket Tapping and Facing Tool
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
This tool serves two purposes. First of all to recut and clean the threads in the bottom bracket shell of the frame. Secondly to face the edge of the bottom bottom bracket shell to ensure an even interface with the bottom bracket.