Park Tool

Steel Bottom Bracket Tool BBT-135-12

Park Tool Steel Bottom Bracket Tool BBT-135-12 is a heavy-duty, precision-machined shop tool designed for confident removal and installation of bicycle components that use a 12-notch threaded bottom bracket tool interface. Built from tough 4140 steel, it’s made to hold crisp engagement under real workshop torque, helping reduce the risk of slipping or rounding shallow, tight, or recessed fittings.

• Precision 12-notch fit - Fits 12-notch threaded bottom bracket tool fittings with a 48–50 mm major diameter (outside of notches) and 46.3 mm minor diameter (inside of notches) for accurate engagement
• 4140 steel construction - High-strength material choice for long service life and consistent performance under repeated installs/removals
• Extra-deep body - Accommodates extra-wide spindles for better access on modern configurations that can block shallow tools
• Low-profile engagement walls - Helps reach recessed lockrings and fittings where bulky tools can’t fully seat
• Three drive options - Use a 3/8" drive fitting, 1" hex, or 36 mm wrench flats to match the torque tool on hand