O-Ring Carb Nut 5/16-18 Alum

The O-Ring Carb Nut 5/16-18 Alum from QUICKCAR RACING PRODUCTS is a precision thumb screw assembly designed for carburetor air cleaner systems and fuel system applications where secure, vibration-resistant fastening is critical. Built by racers for racers, this component serves as a replacement or upgrade part for vehicles where quick adjustments and reliable hold-down strength matter—whether you're fine-tuning a high-performance engine on the dyno or ensuring your marine carburetor stays sealed during rough water operation. The integrated O-ring sealing surface eliminates the need for separate gaskets, streamlining installation and reducing potential leak points.

Machined from aluminum and finished in natural (uncoated) state, the O-Ring Carb Nut 5/16-18 Alum features a 5/16-18 inch thread specification that meets standard automotive fastener tolerances. The thumb screw design allows one-handed tightening without tools, enabling quick adjustments during tuning sessions or emergency repairs without reaching for a wrench. The embedded O-ring provides consistent sealing pressure across the mating surface, preventing fuel vapors or air leaks that could compromise engine performance or emissions compliance. Its lightweight aluminum construction minimizes rotational mass while maintaining corrosion resistance in salt-air environments typical of marine applications.

This fastener is ideal for carburetor rebuilders, marine engine technicians, and performance enthusiasts who demand reliability and repeatability in engine management systems. Whether you're restoring a classic boat engine or maintaining a race-ready automotive setup, the O-Ring Carb Nut 5/16-18 Alum ensures your air cleaner assembly stays sealed and your carburetor adjustments hold firm through vibration and thermal cycling. Installation is straightforward—simply thread onto the 5/16-18 port and hand-tighten until the O-ring compresses fully against the sealing surface. Stock this replacement part in your toolbox to keep downtime minimal when aging fasteners need replacement.