Shimano finally took down its old Australian web site that had all the tech docs back through 2003. (F**K you, Shimano ), so I can no longer find the Service Instructions for square-taper cartridge BBs like UN53 (and UN73?). These use plastic adapters (separate screw-in collars) that accept the 20-spline tool like the main body.
The torque spec for metal cartridge BBs is 35 ft-lb, but what about the plastic side? Seems like a lot for non-metal. Does anyone have an installation sheet for these BBs? The torque specs are on them.