Bulkhead Nut

A bulkhead fitting without its nut is just a fitting stuck in a hole.

Panel-mount plumbing clamps the panel between fitting shoulder and nut, and the nut half wanders off first. The Finish Line Factory Bulkhead Nut is the matching half, in 3AN, 4AN, 6AN, 8AN, 10AN, 12AN, 16AN, 20AN with threads and finish matched to FLF bulkhead adapters. Spares for the drawer, replacements for the one that rolled under the workbench.

Benefits

• The panel clamps up tight and the fitting finally stops rotating with the wrench
• Matched threads run on smoothly instead of galling halfway
• Finish matches the fitting, so the visible side looks intentional
• A spare on hand saves the day the original disappears mid-install

Features

• Sizes: 3AN, 4AN, 6AN, 8AN, 10AN, 12AN, 16AN, 20AN
• Matched thread and finish to FLF bulkhead adapters
• Clamps panel-mount fittings through firewalls, tanks, and panels
• Pairs with a PTFE washer for load distribution
• Sold individually

The Details

A bulkhead joint is mechanical, not hydraulic: the nut and shoulder clamp the panel while the fitting's flare ends do the sealing out at the hoses. That means nut torque is about immobilizing the fitting, with a washer under the nut spreading load so thin sheet metal does not dimple. Hold the fitting flats while torquing the nut, or the whole assembly spins in the hole. On fuel cells and tanks, a PTFE washer between nut and panel protects the surface and keeps the joint serviceable years later. Match nut size to the bulkhead body exactly and keep one spare per size on the bench; they cost little and vanish often.

Kit Includes

• 1x Bulkhead Nut (size per your selection)

Applications

• Sizes: 3AN, 4AN, 6AN, 8AN, 10AN, 12AN, 16AN, 20AN
• Fits FLF Straight and 90 Degree Bulkhead Adapters
• Common uses: firewall pass-throughs, fuel cell plumbing, trunk-mounted system panels
• Pairs with FLF PTFE Teflon Washers