B-Series Flywheel Bolt (12×22 – 12-point Head)

B-Series Flywheel Bolt

This 12-point flange bolt secures the flywheel to the crankshaft on Honda B, F, G, and H-series engines. Eight are required per flywheel. Because the flywheel operates under constant rotational load and high torque, the hardware holding it to the crank is safety-critical — correct thread engagement, clamping force, and bolt condition matter every time the engine is assembled.

These are service hardware. A flywheel bolt that has been torqued and heat-cycled has already done its job once. Reusing stretched or fatigued hardware on a rebuild or clutch job is the kind of shortcut that shows up later as vibration, fretting on the crank flange, or worse. Fresh bolts at every flywheel installation is the standard.

Manufactured to Honda factory specifications for thread form, flange geometry, and tensile strength.

Thread pitch: M12 × 1.0
Head type: 12-point flange
Head size: 17 mm
Body length: 22 mm

Factory Part Number: 90011-PH3-000