Width: 68.5 mm; 0.5 mm oversize to allow for clean up after welding
Relief: On the inside diameter to 1.385"/1.395"
Threads:
1.370"-24, right and left hand; compatible with all modern threaded bottom brackets
Thread length = 0.50"
Left hand thread is identified by a radial groove on the face of the shell
Minor diameter = 1.330"/1.340"
Purge/Vent Holes: Two each 8 mm for the chainstays, two each 14 mm for the seat and down tubes. Hole positions are generic and are positioned to fit most frame configurations.