O.S. Engine OS28309000 GT33 Propeller Seating Washer for Model Engines  [OS28309000]

Product brief: GT33 propeller washer

This propeller washer is an accessory for RC model engine crank shafts, positioned between the propeller and its retaining hardware. As the GT33 item listed OS28309000 by O.S. Engine, it delivers a consistent seating surface so the propeller bears evenly on the prop hub.

Installation is straightforward with the standard tools used for prop mounting. Place the washer over the shaft or adapter, fit the propeller, then secure the nut or retainer to the torque specified by your engine instructions. The component helps to stabilise seating and reduce variation when hardware is tightened.

For bench work the washer enables repeatable prop positioning, which simplifies evaluating minor balance or timing changes. It also serves as a useful replacement part for scheduled inspections and quick swaps during servicing.