Bulkhead fittings are designed to pass through a panel and secure with a locknut. Lustrated above is series 2700 Bulkhead Union and 306 Locknut. The panel hole should be drilled to the "W" diameter specified for that size. Since assembly is the same as the 37 degree JIC threads, see that setup for torpue values and assembly instructions. With the variety of bulkhead fittings that we offer you can have a hose, tube, or quick discount conveniently mounted for easy access.