Rīks Cyclus Tools tap for bottom bracket BSA 1,370"x24TPI for 720140 2 pcs. (720142) TOOL463
With the Cyclus Tools Threader Professional for BSA (1,370" x 24 tpi) you'll generate optimal concentricity of the bottom bracket's thread.
Insert both sides of the threader simultanly to avoid any canting.
The usage of an appropriate cutting oil is necessary.
Attention: letters and marks on the tool refer to the tool itself, not the frame (e.g. "R" means you have to turn the tool to the right, "L" means turn to the left!)