Threaded Insert, 4-40 (4) (DUB391)

Brass 4-40 Threaded Inserts (set of four) are designed to add durable metal threads into wood, letting you mount engines to wood mounting rails and create wing hold-downs. They provide a simple, reliable way to add threaded holes in wooden surfaces where other fasteners aren’t feasible.

Made from brass for corrosion resistance and solid engagement with wood, these inserts deliver a reusable mounting point for screws that secure aircraft wings and other components. They’re especially useful when blind nuts aren’t a good fit or when space is limited, offering a compact, sturdy solution for wooden builds.