Locknut

The AEROQUIP Locknut (FBM2099) is a precision bulkhead fitting nut engineered for fluid power systems and hydraulic applications requiring secure, leak-proof connections. This 4 AN-sized locknut serves as the critical fastening component in high-pressure hydraulic assemblies, where reliable thread engagement and vibration resistance are non-negotiable. Sold as a pair, these locknuts are essential for technicians, mechanics, and engineers working with aircraft, industrial machinery, or performance automotive hydraulic systems that demand aerospace-grade reliability.

Manufactured from aluminum and finished in blue anodize, the AEROQUIP bulkhead fitting nut offers corrosion resistance and lightweight construction without sacrificing strength. The 4 AN thread specification ensures compatibility with standard AN-size hydraulic connectors and fittings, while the anodized surface protects against oxidation in harsh operating environments. Blue anodizing serves both as a functional protective layer and as a visual identifier for AN-standard components, streamlining system assembly and maintenance. The compact design—measuring 1.65 × 0.55 × 4.05 inches and weighing just 0.04 lbs per unit—facilitates installation in tight spaces without compromising holding power or sealing integrity.

This locknut pair is ideal for anyone assembling or maintaining hydraulic bulkhead fittings in aircraft fuel systems, pressure gauges, filtration units, or custom hydraulic manifolds. Installation is straightforward—simply thread onto the bulkhead fitting body and tighten against the mating component to create a sealed, vibration-resistant joint. The pair format accommodates dual-fitting installations or provides a spare for redundancy. Whether you're rebuilding a legacy system or constructing new hydraulic infrastructure, AEROQUIP FBM2099 locknuts deliver the precision engineering and durability expected from an industry-leading supplier of fluid power components.