The Park Tool Bottom Bracket Tool BBT-22 is built for the straightforward work of installing and removing splined 20-tooth bottom bracket cups — the kind found across a wide range of external and cartridge-style bottom brackets. Investment cast steel construction gives it the rigidity needed for stubborn cups, while a flat tooth profile maximises engagement to reduce the risk of slipping and rounding out the interface. The 20-tooth spline pattern covers a broad spectrum of bottom bracket standards, including splined ISIS Drive and Octalink designs — and the tool is cut to clear oversized spindles used in both systems. It accepts a 3/8" drive torque wrench or ratchet driver, a 32mm wrench, or a 1" wrench, so it works equally well at a workshop bench or on a home repair stand. Park Tool Bottom Bracket Tool Specs at a Glance SKU: BBT-22 Drive interface: 20-tooth splined profile Material: Investment cast steel Compatible drive types: Splined ISIS Drive and Octalink bottom bracket cups Driver compatibility: 3/8" torque wrench, 3/8" ratchet, 32mm wrench, or 1" wrench