Twenty splines on a 32mm diameter — that one measurement tells you whether this is the right tool for your bottom bracket or not. Park Tool's BBT-32 fits that specific internal spline pattern used across a wide range of cartridge bottom brackets from Shimano, Truvativ, Race Face, FSA, and others. If you've pulled the crankarms and see a ring of 20 evenly spaced splines inside the cup, this is the tool that engages them.

The BBT-32 is the compact sibling of Park Tool's BBT-22. Both tools share the same 20-spline interface and fit the same bottom brackets. The difference is in how you drive them. The BBT-22 accepts a 3/8" ratchet or torque wrench through a socket drive fitting, while the BBT-32 uses 32mm wrench flats and requires an adjustable wrench or 32mm box wrench to turn. That compact form factor makes the BBT-32 sit closer to the bottom bracket cup, which reduces the cam-out force that can cause the tool to slip under heavy torque. If you're dealing with a seized cartridge bottom bracket, you can thread a crank bolt with a washer through the center of the BBT-32 to lock it against the spindle — a trick the BBT-22's taller profile makes more difficult.

The tool's center bore clears the oversized spindles found on ISIS Drive and Shimano Octalink cranksets, so you won't run into interference when engaging the cup. It also fits some crankset lockrings, including certain Race Face models. This is an internal cartridge bottom bracket tool — it does not work with external bearing cups like Shimano Hollowtech II, SRAM GXP, or other 16-notch systems. Those require a different tool entirely (Park Tool's BBT-9 or BBT-69.4, for example).