What is a union bolt?

A union bolt is a hollow or specially shaped fastener used in some fuel, oil, brake, hydraulic, or fluid-line systems to secure a fitting while allowing fluid to pass through. On Yamaha parts pages, the exact bolt union should be matched by OEM part number and application.

Before ordering a Yamaha bolt union, confirm the part number, thread size, sealing washers, torque specification, and the system where the bolt is used. Similar-looking union bolts may not interchange safely.

90401-10106-00 - BOLT,UNION