The job
A 16-notch external-cup socket with a 3/8-inch square drive and one-inch wrench flats.
Park Tool · Bottom-bracket cup tool
Park Tool BBT-19.2 Bottom Bracket Socket
A 16-notch external-cup socket with a 3/8-inch square drive and one-inch wrench flats.
$19.95Nov 7, 26, 12:52 AM · New York
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- Cup contact 16 notches; 44–45 mm major / 42.7 mm minor diameter
- Square drive 3/8 in
- External wrench flats 1 in
Cup contact
16 notches; 44–45 mm major / 42.7 mm minor diameter
Plan the torque-wrench connection
Match the drive size and follow the component procedure. The socket does not measure torque by itself.
What this choice changes
A steel socket with two driving interfaces
The BBT-19.2 is the socket-format choice for a matching 16-notch external bottom-bracket cup. Its 3/8-inch square drive can be paired with a suitable manual ratchet or torque wrench, while one-inch external flats provide a second driving option. Neither driving tool is supplied, so it makes most sense when you already have one or are building a workshop around separate handles.
The contact measures 44–45 mm at the major diameter and 42.7 mm at the minor diameter. The hardened chromoly body is a different format from the handled BBT-9, rather than a different cup standard. Check the exact cup model: the maker names specific Shimano and matching GXP, MegaExo and X-type applications, not every cup from those brands.
One limit matters when planning several jobs around one socket: Park Tool does not recommend this model for shallow 16-notch disc-rotor lockrings. It also excludes impact drivers and other power tools. Choose a tool approved for the actual component instead of assuming that a similar notch count makes the sockets interchangeable.
Specifications & supplied details
| Detail | Specification |
|---|---|
| Cup contact | 16 notches; 44–45 mm major / 42.7 mm minor diameter |
| Square drive | 3/8 in |
| External wrench flats | 1 in |
| Body | Hardened chromoly |
| Supplied | One socket; driving wrench separate |
Choose for your actual setup
Plan the torque-wrench connection
Match the drive size and follow the component procedure. The socket does not measure torque by itself.
Keep cup and rotor jobs separate
A shared notch count does not overcome this model’s shallow rotor-lockring exclusion.
Fit checks & limits
- Not recommended for 16-notch rotor lockrings with shallow engagement.
- No impact-driver or other power-tool use.
- The selected offer is labelled Silver while its source photograph shows a dark finish; a particular finish is not confirmed.
Questions before you choose
Is a ratchet or torque wrench included?
No. This is the socket. Supply a compatible 3/8-inch drive tool or a wrench for its one-inch external flats.
Does it add a new cup size compared with BBT-9?
The main cup fitting is the same family. The difference is the socket format and its driving interfaces; the BBT-9 also has a handle and cap-tool function.
Can I use an impact driver to loosen a tight cup?
No. Park Tool excludes impact drivers and other power tools for this socket.
Guides for this choice
Buying guide ↗
Match the Component Contact Before the Drive Handle
Separate the surface that touches the bicycle from the interface that accepts your wrench, then check access and any required retaining accessory.
Buying guide ↗Choose a Torque Range, Indication and Usable Bit Set
Compare measuring range, direction and fastener access before judging a set by bit count or a ratchet-strength figure.
Buying guide ↗Choose Crank Pullers, Cap Tools and Bottom-Bracket Contacts
Separate arm extraction, cap adjustment, cup engagement and counterholding to buy the contacts your actual drivetrain needs.
Alternatives to compare
Other equipment to consider
Selected listing details, manufacturer information and source images were compared. No hands-on trial or universal fit is claimed. Product identifier: B00L4XCMR6.