Acme Automotive Prop Nuts & Thrust Washers
Acme Automotive Prop Nuts & Thrust Washers
When it comes to keeping a propeller properly seated and a lower unit protected on the water, few components are as deceptively important as prop nuts and thrust washers. Acme Automotive brings its trusted parts expertise to the Prop Nuts & Thrust Washers category, offering marine hardware engineered to keep your propeller assembly secure under the demanding loads of everyday boating.
What Prop Nuts and Thrust Washers Actually Do
Understanding these small but critical components helps explain why quality matters so much. Thrust washers sit on the propshaft between the lower unit and the propeller. The thrust washer transfers thrust to the shaft and protects the gear housing and its seal from contacting the rotating propeller. Without a properly fitted thrust washer, forward motion in gear can allow the propeller to slide forward, causing potentially serious damage to the lower unit housing.
The prop nut secures the prop to the shaft and helps transfer reverse thrust to the shaft, making it the final — and essential — fastener in the entire propeller assembly. A typical recreational boating propeller is mounted on a splined propshaft with a thrust washer, spacer, washer and nut, with some provision to keep the nut from turning loose, such as tabs on the washer or an additional cotter pin. Every component in this stack must be the correct fit for its specific engine and drive application.
Thrust washers also perform a secondary but equally important function: the thrust washer helps to keep the propeller centered on the shaft when the soft inner prop hub fails to do so under adverse high-torque conditions. In performance or high-stress scenarios, a worn or mismatched thrust washer can lead to vibration, premature hub failure, or worse.
Why Fit and Material Selection Matter
Thrust washers are made from many different materials, and are selected for the best combination of performance, maintenance, and price. For marine applications on outboard and sterndrive systems, matching the washer material and geometry to the specific engine manufacturer's spec is critical. Because each of the parts in the prop assembly performs an important function, it is important to use the correct parts and to install them all as intended. Using an incorrect or worn thrust washer can lead to fore-and-aft play on the shaft, allowing the propeller to hammer the washer every time the throttle is applied or the drive is shifted.
Acme Automotive in the Marine Hardware Category
Acme Automotive has long been a reliable source for precision-fit automotive and marine hardware. Their prop nuts and thrust washers are sourced to meet the dimensional tolerances that specific engine families demand — whether you're maintaining an outboard or a sterndrive setup. For boaters performing routine propeller maintenance or replacing components after a strike, having the right prop nut and thrust washer on hand is the difference between a confident installation and a costly trip back to the dock.
Browse the full selection of Prop Nuts & Thrust Washers or explore the complete Acme Automotive catalog to find the marine hardware, fasteners, and accessories that keep your vessel performing at its best.