A lot of the questions we get in the prop department at iboats.com have to do with the hardware that is needed with boat propellers. Prop hardware ensures a good fit between the motor and prop, and secures the propeller in place. Not all props use the same hardware, but they typically use a combination of the following five pieces:
- Thrust Washer – These go between the lower unit and the propeller, providing a snug fit.
- Spacer – This is the first piece of hardware on the boat prop shaft after the propeller.
- Washer – Mercury uses tab washers. The tabs are bent to lock with the spacer. Other engine manufacturers use flat washers between the spacer and nut.
- Prop Nut – Mercury uses a locking nut to complete their propeller hardware. Other boat engine manufacturers use a castle washer.
- Cotter Pin – Propeller applications using a castle washer also require a cotter pin to help hold the nut in place.
You can find prop hardware at iboats.com. Remember, always consult your engine manual for hardware requirements specific to your engine.